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He picked it up and studied it. "Four T's," he said, "three S's, three A's, and three O's. That ought to give us a clue."
Again he turned to the dollar and began to study it, turning it slowly round, counting the scratches this way and that, making geometric figures of them. Four heads peered over his shoulder as he worked silently with his pencil.
"I can make nothing of it," he said after a time.
Again he sat in deep thought, his fellows meanwhile once more examining dollar and disc and the figures their leader had made on the paper.
"Four T's," repeated Captain Hardy after an interval. "Surely that ought to give us a clue."
Once more he studied the penciled disc. Then he turned to the dollar and again examined its markings. He suddenly exclaimed, "Here are four scratches in a straight row." His eyes began to shine. Slowly he turned the coin. "And here are three in another row, like this," and he indicated the positions of the scratches on the paper disc. "You notice that each row runs from the centre of the coin toward the edge. Let's see if there are any more rows."
Very slowly he turned the dollar. "And there are three in a row," he said, indicating the scratches with his pencil, "and here are three more. You notice that the rows all radiate from the centre, like spokes in a wheel. I believe we are getting somewhere, boys."
"'Like spokes in a wheel,'" repeated Roy to himself. "Rows of letters like spokes in a wheel. Four scratches in one row or spoke—these must be the four T's. Three scratches in these other rows must be O's and A's and S's. I've got it! I've got it!" he suddenly shouted. "There must be as many spokes as there are letters in the alphabet."
"I believe you are right, Roy," said Captain Hardy, looking up with a gleam in his eyes. "That's exactly what I am beginning to think. We'll soon see if you are right. Make me another disc."
With a pocket rule he measured the diameter of the dollar. "Practically an inch and a half," he announced, putting down the figures 1.5 on paper. He multiplied those figures by 3.1416.
"That," said he, pointing to the resulting figures, 4.71+, "represents the circumference of a dollar. Now we'll divide the circumference by 26, the number of letters in the alphabet."
He performed the division. "Eighteen one-hundredths of an inch," he announced. "That's practically a scant fifth of an inch. We'll call it so, anyhow," he continued as he marked off the space on a sheet of paper with his rule. "Each sector," he said, "gets exactly that amount of space on the circumference."
He pulled open the drawer of the desk and began to rummage through a tray full of pens, pencils, and other drawing materials. "I wonder if there is such a thing as a pair of dividers here," he remarked. And a moment later he exclaimed "Good!" and drew forth the compasses he was looking for.
He set his dividers according to the space he had marked off with his rule, then proceeded to divide the circumference of the new paper disc. When he had gone completely round the disc, he seized pencil and ruler and began to draw lines from centre to circumference—the spokes of his wheel—each spoke running from the dot in the centre to one of the points indicated by the dividers. When he had finished, the disc was divided into twenty-six equal sectors, like tiny pieces of a pie.
"We shall soon know whether you are right or not in your guess, Roy," said Captain Hardy.
He laid the dollar beside the disc and began to copy on the disc the marks on the dollar. "We'll put four marks in this sector," he said, making four dots with his pencil. "They are like those four scratches here," and he pointed to the four marks in a row on the dollar. "They must be four T's. At any rate we'll call this the T sector. On the dollar you notice this row of three scratches—the next sector to the left of the T sector. You remember we had three O's, three A's, and three S's. These three scratches must, therefore, be O's, A's, or S's. Since they are next to the T's, they are doubtless S's. I'll mark the sector so anyway. That gives us the T sector and the S sector. If we are on the right track, then the sector to the left of the S space is the R sector, and so on. I'll mark the disc that way, anyhow."
Slowly he turned the disc around, putting a letter at the bottom of each sector. When he had finished, he had completed the alphabet. About him clustered his four comrades, too deeply interested to speak. They hardly even breathed.
"Take this paper, Roy," said Captain Hardy, "and tell me how many times each letter in the message appears."
Roy took the paper on which Captain Hardy had made his numerical enumeration. "Three A's," he said.
Captain Hardy made three marks in the A sector.
"No B's, no C's, and two D's."
The D's were scored. So they went through the alphabet. When they were done, the markings on the disc were practically a duplicate of those on the dollar, for Captain Hardy studied the dollar each time before marking the paper disc.
"That's it," cried Willie. "That's it exactly."
"It's right so far as it goes, Willie," said their leader, "but we haven't all of it yet. Suppose I hand you a disc with four T's, three S's, two Z's, three L's, and so on. Could you make a message out of it?"
Willie studied the disc on the desk. "No," he said, "I couldn't. I shouldn't know how to arrange the letters to make words out of them."
"Neither would anybody else," continued Captain Hardy. "Those spies have some way of knowing how to tell the order in which to read these letters."
For some time he sat studying the scratches on the dollar. The four boys were quiet as mice, each trying to solve the problem that stood between them and complete mastery of the cipher.
"You said that the metal disc resembled a spider's web," began Captain Hardy, talking more to himself than to the boys. "We know what the straight lines—the spokes—are for. The concentric circles must be to indicate the order of the letters. Let me see." Again he studied the dollar closely. "Some of these marks are near the centre of the disc, some half-way between centre and circumference, and some close to the outer edge. I believe the secret lies there."
"Listen!" cried Willie of a sudden. "When a spider spins a web, she begins at the centre and works outward. Maybe these spies write their messages in the same way."
"Willie," cried Captain Hardy, "you've hit it exactly. You're as good a reasoner as you are an observer. Now we'll begin at the centre and spin this message outward. What's the first letter?"
"T," said four voices together.
The captain took his dividers and found the scratch nearest the centre of the disc. In the same sector with this scratch were three other scratches in a line.
"It's a T," he announced, "just as it should be."
With his dividers he found the letter next nearest to the centre. It stood alone. "That's a W," he announced.
Rapidly he located the scratch the third nearest to the centre. "And that's an O," he said, looking up with flashing eyes. "We need go no farther. We have the entire secret. We have deciphered their cipher."
A cry of exultation arose.
"To-morrow," continued Captain Hardy, "we will get a piece of transparent celluloid and make a disc like their own. We can ink in the circles and the radius lines and our disc will be almost a duplicate of theirs, except that our disc will be solid while their discs have open spaces between the circles. But that is only a detail. We can read their cipher as well as if we had one of their own discs."
"Wait," cried Willie, as his comrades started to cheer again. "What is the scratch on the milled edge of the dollar for?"
"That," replied Captain Hardy, "is to indicate how the disc is to be placed on the dollar. That scratch is exactly between the Z and the A sectors. It shows where the alphabet begins. Now we have their entire secret."
A piece of transparent celluloid, furnished by their host from a broken side curtain of his automobile, supplied Captain Hardy with the material needed for making the disc that was to be the key to future communications of the enemy. Carefully he cut the celluloid the size of a dollar, then marked the exact centre of it. Next he clamped the disc on the captured coin. Between the rows of letters he scratched in the straight radius lines—the spokes of a wheel. Then Captain Hardy put the end of one arm of his dividers in the dot at the centre of his disc, and swept the other arm around, scratching a circle just outside the first letter in the message—the innermost T. Examination showed that this circle fell just inside of the second letter in the message—the W. Adjusting his calipers, the draughtsman made a second circle, just outside of this second letter. A third circle fell between the first O and the second T of the message. So Captain Hardy continued, each succeeding circle falling just outside of the succeeding letter in the message. When he had finished, his disc contained twenty-three concentric circles, between which could plainly be seen the bright dots or scratches in the dingy dollar.
"Whew!" said Captain Hardy, as he laid down his dividers. "That's pretty fine work—twenty-three circles within a space of an inch and a half. I'll wager a watchmaker made their pattern for them. The solid parts of their metal discs can't be much larger than these lines I have scratched on the celluloid. You were right when you named it, Willie. The parts of it must be just about as thick as a spider-web."
The boys passed the dollar and its superimposed disc from hand to hand, examining them with eager interest.
"Suppose they wanted to send a message with more than twenty-four letters in it," said Roy. "How could they do it? I'm sure some of the messages we intercepted had more than twenty-four letters in them."
Captain Hardy picked up the disc-covered dollar and studied it intently. "I suppose," he said after a time, "that they would put more than one dot in the same circle, and the dots would be read in the same way they are now. The one to be read first would be nearest the centre of the coin, and so on. Or they could write on several coins, each coin being numbered in some way, and corresponding to a paragraph in a composition."
Again he studied the dollar closely. "Clever!" he said admiringly. "Mighty clever! Who would ever dream that those tiny scratches meant anything? Many a time I've seen a dollar scratched and nicked a deal worse than this one is, though they've evidently chosen a battered one so that their own marks will be less noticeable. Why, that coin might have passed through our hands a hundred times, and if we had not actually seen it marked we should never dream it said anything other than 'In God We Trust.' We've had a great stroke of luck, boys."
He paused and meditated. "I wonder if it is luck," he went on. "May not the motto on that dollar explain our good fortune? Perhaps it is Providence rather than blind luck that has guided us. At any rate let us hope so. Now I'm going to report to the Chief. Won't he get a surprise?"
And Captain Hardy left his subordinates, chuckling at the prospect of the Chief's astonishment.
But it was Captain Hardy who had the surprise. Instead of the stern, silent, brusque man he had become accustomed to, Captain Hardy found the Chief smiling and talkative. As his eye fell on Captain Hardy, the Chief rubbed his hands with apparent satisfaction. Evidently something had happened that had put him in an extremely good humor.
"Ah! Captain Hardy," he said, "we beat you to it this time. I already know what you have come to tell me. But I am glad to see you just the same. One of our operators," continued the Chief, "happened to be shifting his tuning-coil when our friends, the enemy, were sending their message yesterday afternoon, so that I have all the latest spy news."
He paused and smiled at his astonished visitor. "You see," he added, a real Irish twinkle coming into his eyes, "the secret service is not so slow after all."
"Congratulations!" cried Captain Hardy, in the same spirit of fun. "The secret service is improving. But I have some news that may make my trip not altogether without interest to you."
The Chief interrupted him. "We know who the man is that has been telephoning to your Staten Island grocer about sugar," he said. "When he called up yesterday afternoon, the telegraph operator flashed the tip to my man, who happened to be on duty within a few doors of the place the man was talking from. Of course my man spotted him and trailed him. The fellow proves to be a clerk on one of the piers where transports are loading. His position gives him no opportunity to get aboard the ships, so he does not know what goes into the transports. But he does know how many boats are loading and about when they will sail. Evidently he is afraid to telephone directly to any of the better known German agents we are watching, and as far as that goes he may not even know who they are. I suppose this plan of communicating with Staten Island is to give the spy there a chance to observe the transports as they sail from the harbor, and see if he can learn anything about their cargoes. We have put this steamship clerk under observation and from now on he will be watched night and day. We're closing in on them fast."
"Congratulations!" cried Captain Hardy again, this time in sober earnest. "You are doing excellent work. Now when you hear what we——"
Again the Chief interrupted him. "Oh! I haven't told you allmynews yet, not by a long shot," he said. And again the head of the secret service rubbed his hands together. "We know who the driver of the wireless motor-car is. I don't mean we know the name he's using. Anybody could get that out of a directory. It's Sanders. But we know who he really is. And that's why we feel so good to-day. He's a man we've been looking for for months. He is one of the German agents implicated in the papers we seized in Wolf von Igel's office. The secret service has been more than anxious to discover his whereabouts. Now we have him, for he's under observation and cannot escape us.
"He came to this country about a year before the war started," continued the Chief, a gleam of satisfaction shining in his eyes, "and bought out an insurance agent who made a specialty of insuring suburban properties. From the beginning, he made a practice of visiting the properties that he insured. This took him about a good deal and gave him an excuse for being so much in a motor-car. Ah! What an ideal situation for a spy! Clever, aren't they?"
But the Chief gave his visitor no chance to reply to his query. Smiling again, he went on, "But even this is not all. Of course you understand, Captain, that your boys are not the only amateurs helping us out in this pinch. Ever since we became convinced that the Germans have a line of secret wireless stations by which they are relaying news to their agents in Mexico—for we're morally certain that is where these messages go—we've had trusted amateurs helping us just as you have helped us—by listening in. Some of them have been at it for weeks. When we could get no trace of secret messages along the direct route to Mexico, where they would naturally have their stations, we began to suspect that the Germans were using a round-about route in the hope of deceiving us completely."
"And you've located some of them?"
"Exactly. Your boys will tell you that yesterday was one of those days when radio communication is at its best—when an operator picks up sounds that at other times he could not possibly hear. The result was that we picked up yesterday's secret message at half a dozen different points. Where do you think the first one was?"
"Give it up."
"Buffalo—north instead of south. Clever, eh? Then we got it near Detroit, and Milwaukee, and Omaha, and Santa Fé. Finally one of our listeners picked it up at Socorro, a place about one hundred and seventy miles north of El Paso. Now we know the line of their stations. We'll set a regiment of amateurs to listening in along that line and we'll locate every station in it in no time. Then we'll grab all their agents at the same time in one big raid and wipe out this spy system for good."
"That is great news," said Captain Hardy, his eyes sparkling with interest. "Great! You certainly have cause to feel good."
"For a little while," replied the Chief, "I thought I had even more good news. But it proved to be a false alarm."
"What was it?" inquired Captain Hardy as the Chief stopped speaking.
"Oh! Simply this. Some time ago one of our listeners caught an earlier message near Socorro, which gave us a hint as to where the messages were crossing the border. We at once sent a number of expert army wireless men into that part of the border region to listen in. One message was picked up at a point fifty miles north of the boundary, but it was very faint. Along the line itself the radio men have never detected a sound. Yet your boys are intercepting the messages here, so we know that they are being sent regularly. That made us think that perhaps the messages were being telephoned the last lap of the journey and carried over the line by a person."
"I have no doubt that your theory is correct," said Captain Hardy.
"Well, last night we thought for a time that we had the man who was carrying the messages. When my operator here picked up the message yesterday afternoon, I instantly sent a message to my subordinate in charge of the work in the El Paso district, telling him of the sending of the message and urging extra vigilance. Yet not one of the radio men heard a sound. But in the middle of the night my men grabbed a Mexican who had slipped past the armed guards and was starting to wade across the Rio Grande to Mexico."
"Excellent!" cried Captain Hardy.
"Good enough as far as it went," said the Chief, with a wry face, "but it didn't go far enough. The fellow was only a smuggler."
"Are you certain, Chief?"
"Sure as preaching, worse luck."
"Was the man searched thoroughly?"
"Now, Captain, what do you think the secret service is, anyway? Was he searched! It would make your eyes pop out if you'd see the way we go through a man. We strip him and give him a lemon bath to bring out any secret message that might be written on his skin, and we take his clothes apart scientifically, I tell you. No, this fellow had nothing incriminating on him. After a grueling examination, he admitted that he had crossed the line to smuggle in some tobacco. However, it's only a question of time until wedoput our finger on the missing link. Then for a great raid!"
"How I shall welcome that day," said Captain Hardy. "This spy business is never absent from my thoughts, with its menace to our boys on the ocean."
"I think that you will soon be free to go back to the army," said the Chief. "Your work is about done. This thing is coming to a head fast now. But of course I shall need your boys to listen in for a time, so that we can know what the Germans are sending. But there will probably be no more real work for you. We certainly are grateful for the help you gave us, though. We have been terribly crowded these last few weeks."
In his pride at the work his boys had done, Captain Hardy momentarily forgot the errand that had brought him to the Chief's office. He stood before the head of the secret service, smiling happily. Again he began to think of that long chain of secret wireless stations, so sinister and so menacing, with voice crying treachery to voice through the air, carrying word that at any time might cause the murder of thousands of our brave soldiers. Mentally he journeyed along the line of those stations—from New York to Buffalo, to Detroit, to Milwaukee, to Omaha, to Santa Fé, to Socorro, to Mexico. With quick imagination he pictured the scores of little secret stations needed to carry those treacherous messages across so vast a span of earth. Some he saw skilfully hidden in forests, as the wireless had been concealed at the Elk City reservoir. Some he pictured in abandoned farmhouses. Others he saw in barns, in the stacks of ruined factories. And some he imagined as flinging their voices abroad amid the burning plains of the arid border-lands. But he could not picture to himself the invisible messenger that took the word across the boundary. He could not fathom the mystery, he could not picture to himself the missing link in the chain. As was always the case with him, his mind began at once to grapple with its problem—in this instance the riddle of the missing link. He actually forgot where he was.
"I wonder," he said, though he was really talking to himself, "what was done with that smuggler."
"We clapped him into jail to await trial for smuggling," said the Chief.
Captain Hardy came to himself with a start, and smiled. "You say they got nothing incriminating on him," he remarked. "Did your men find anything at all?"
"Only the money he had gotten for his tobacco."
Mechanically Captain Hardy had thrust his hand into his pocket. As the Chief answered the question, Captain Hardy's fingers came in contact with a silver dollar and a disc of celluloid. Of a sudden an eager light flashed into his eyes. "What kind of money did that Mexican have?" he demanded.
"Some silver," said the Chief indifferently.
"Of what denominations?"
"Dollars. He had three of them."
"What was done with that money?" asked the captain with an earnestness that was almost tragic.
"Oh! The greaser made such a disturbance that the jailer let him keep it. He's got it with him in the jail."
A great sigh burst from Captain Hardy's lips. "Telegraph your men instantly," he cried, "to get those dollars. That Mexican is no smuggler. He's a spy. He's the man who carries the messages across the border. The messages are on the dollars. And here's the key to the cipher!"
And he drew from his pocket and laid before the Chief a battered silver dollar and a curiously marked celluloid disc.
"Was he surprised?" cried the four boys of the wireless patrol, as their captain entered the living-room after his trip to the secret service offices.
Captain Hardy chuckled. "I think he was," he said. "But for a time it was I who was surprised. The Chief knew from his own men all about yesterday's message. One of them picked it up. What's more, he has a lot of amateurs in different parts of the country listening in, just as you are doing, and they picked up yesterday's message at enough different points to indicate the line of the secret stations we are after. The messages are crossing the border somewhere near El Paso. But the Germans are getting them across in some way other than by wireless. They know we'd spot their outfit quick. The Chief thinks some one telephones the messages the last lap and that a messenger carries them into Mexico."
"And what about the dollar and the disc?" asked Roy. "What did the Chief think of them?"
"Well, he was surprised. And what's more, we got hold of that dollar at exactly the right moment. The secret service men arrested a Mexican who was wading the Rio Grande at El Paso last night. They searched him and found nothing on him that seemed incriminating. They questioned him and the fellow finally said he had smuggled some tobacco into this country, so they put him in jail as a smuggler. The fellow had some money he had gotten for his tobacco—and it was three silver dollars! The secret service men down there knew nothing of what we have found out here, so they gave the fellow back his money. But I am morally certain that their man is the spy who carries the messages across the border."
"Of course," cried Willie. "What else could he be—sneaking across the boundary with three silver dollars."
Everybody laughed.
"It doesn't follow that he's a spy, just because he has three silver dollars. He may be a smuggler, all right enough. But I believe the smuggling is just a blind. If he were a genuine smuggler, he'd bring more than three dollars' worth of stuff across."
"What have they done with his dollars now?" asked Roy eagerly.
"I don't know, Roy. The Chief got into instant touch with his men at El Paso as soon as I showed him the dollar Henry got. But I left before I knew what the outcome was. However, I have no doubt they will find that the dollars are what we suspect them to be."
"Gee!" said Willie. "To think that the wireless patrol found out about those dollars!"
"I guess the secret service knows by this time that boys are worth something," smiled Roy. "Before we get through, they may think so even more."
"You're certainly not increasing in modesty," laughed their leader.
"Well, I don't care," said Roy hotly. "It makes me tired. Everybody says, 'Oh! They're only boys.' Of course we're only boys, but look at what we've done. Why, the wireless patrol has got the best set of fellows——"
But Roy's protest was smothered in a burst of laughter from his fellows.
"Well, I'm glad you feel so good over what we've been fortunate enough to accomplish," said Captain Hardy, "for I fear there will be no more excitement for you. The Chief says his men now have the spy business well in hand, and that all he wants of us from now on is merely to stay here and catch their messages until he is ready to make his raid."
"Just what I was saying," burst out Roy indignantly. "They won't let us in on their raid because 'we're only boys.' But who was it caught the dynamiters, if it wasn't 'just boys'? The men couldn't do it. They tried twice and failed. Gee! It makes me tired."
"Never mind, Roy," said Captain Hardy smiling. "Even if we don't have any further taste of excitement, we can always remember that we had a big part in catching these spies—for they're going to be caught, sure. And you mustn't forget that if we stay here and do well the part assigned to us, we are helping just as much as the men who actually round up the spies. You know Milton says 'They also serve who only stand and wait.' If there aren't any reserves to stand and wait behind the lines, the men on the firing-line do not dare to push ahead. And besides, Roy, it is seldom that four boys play so important a part in great deeds as you four boys already have played."
"Four boys and a man," corrected Henry. "Without you we could never have gotten anywhere," and Henry looked affectionately at his captain.
"Oh! Yes, I had a part in it," agreed the captain, "but it was only a part."
"But you read the ciphers," protested Henry. "If you hadn't done that, we could not have made any headway at all."
"And who caught the messages for me to decipher? The reason we have gotten along so well is because we work together so perfectly. I want to thank you boys for being so faithful. I've given you many hard tasks to do."
"After our experiences at Camp Brady," said Lew, "we couldn't do anything else than be faithful. We know by experience what happens when we don't do our duty."
"Then you are going to listen in during the remainder of the spy hunt," said Captain Hardy, with an affectionate smile, "just as faithfully as though your work weren't already done and the spice gone out of it. I know it will be dull and uninteresting, boys, but you've made such a fine record that I don't want you to fall down now. So be very careful—if only for my sake."
"They've never talked once," said Henry ruefully, "excepting after the transports sail. I don't suppose they ever will except when the ships go out. We'll have to listen to nothing for twenty-four hours a day. But we're going to do it just the same."
He rose and walked toward the wireless room. "It's back to the mines for me," he added. And he disappeared through the doorway of the wireless room.
But hardly had he sat down and clamped the receiver to his ears before he cried out. His fellows came flocking into the room. Henry was swiftly writing a string of letters on a sheet of paper.
"Something of moment must be afoot," said Captain Hardy, in a low voice, "for them to be talking at this time. It must be important, indeed."
"It's a long message," whispered Willie, as Henry continued to fashion letter after letter.
"Something tells me it is important," repeated Captain Hardy. "What can it be? You don't suppose the secret service men have alarmed them, do you?"
Henry finished his writing and laid down his pencil. His chief picked up the sheet of paper and scanned the long line of letters Henry had made, like this:
EEANNRDBOEUNRYWSEUTTERONSNNFEEIAYWMNVTTASANXJULEIGOKWSNVATYIZLETK
"Sixty-five," he said aloud, after counting the letters carefully.
A frown came over his face as he stood looking at the paper in his hand. "Sixty-five," he repeated. "All their other cipher messages have made four even lines. You can't divide sixty-five evenly by four. Boys, I believe—but we'll make sure first."
He sank into a chair, laid the paper on the desk, and arranged the letters according to the old plan, thus:
EEANNRDBOEUNRYWSEUTTERONSNNFEEIAYWMNVTTASANXJULEIGOKWSNVATYI
"I don't know what to do with the five letters left over," he said, as he laid down his pencil. Then as he ran his eye down column after column and across each line, he continued, "But I guess it makes no difference. It is just as I thought. I feel more certain than ever that something of great importance is afoot. They've switched to another cipher."
For some moments there was a complete silence in the room. The members of the wireless patrol looked at one another in astonishment, questioning with their eyes the meaning of this new turn of events. Captain Hardy sat staring at the message before him, his brow wrinkled, his eyelids drawn close together, trying to find some new clue to the puzzle before him. And until he spoke, the lads of the little patrol forbore to utter a sound. So for some time the room remained as silent as a tunnel.
At last the captain glanced up from his paper and noted the intent looks bent upon him, and the deep silence. He shook off his abstraction.
"It looks as though we were up against it," he said. "Every minute I feel more certain that something serious has happened. Why should they be sending radio messages at this hour, when they have never sent them before excepting after the transports sailed? And why should they now use a new cipher? Their plan evidently was to use radio communication as little as possible, lest they be detected. So they sent nothing by wireless but the most important news—the news of ship movements, which had to be got to Germany at once. All other messages they conveyed in some slower but safer way. We know they used the telephone, and sent messages by a boy, and wrote on dollars, and carried messages by motor-car, and probably sent code letters through the mails. For all ordinary correspondence they used these slower, safer methods. Only when they absolutely had to, did they employ the wireless. So we must assume that they had to now."
He paused and glanced from face to face. "But why the change of cipher?" he continued. "It must be because they fear that the old cipher will be understood."
Again the captain fell silent. "What can have happened?" he inquired soberly, "that makes the use of wireless so imperative? What can it be? Only something new and unforeseen. And what could there be new and unforeseen except the detection of their plot? More and more I am convinced that these plotters have been alarmed."
He fell into a brown study for a moment. "This message can mean nothing else," he said after a little. "It is imperative that we learn what it is at the earliest possible moment. Make four copies of the message you took, Henry."
Captain Hardy's first lieutenant took the paper from his leader's hand and on four sheets of paper copied the string of letters he had picked from the air.
"Now, boys," said the leader of the patrol, when the copies were complete, "put your thinking caps on. Each of you take one of these copies and see what you can make of it. You know how we deciphered the other cipher."
In another moment four boys were wrinkling their foreheads as they bent over the cryptic strings of letters. And over the room came a hush deep as midnight's.
For a few moments nobody broke the silence. Each boy was busy with his own thoughts.
Henry was scowling at his paper. Willie was studying the letters before him, as in earlier days he had studied the landscapes about Camp Brady and the Elk City reservoir. Lew already had a hopeless look on his face. At threading the forest he was second to none in skill; but at untangling mental puzzles, he had small ability. The nimble-witted Roy was already setting about his task with that keenness so characteristic of him.
"Sixty-five letters," he said to himself. "If this cipher is anything like the other, those letters must be arranged in columns of equal size."
For a second he sat scanning the letters. Then he muttered, "What will divide sixty-five evenly?" And a moment later, he answered his own query by adding, "Five, and thirteen."
He paused and again ran his eye along the row of letters. "If this cipher works like the other there must be five rows of thirteen letters each, or thirteen rows of five each. I'll try the five rows first. That's more like the other cipher."
Swiftly he set down the five rows of letters, thus:
E E A N N R D B O E U N RY W S E U T T E R O N S NN F E E I A Y W M N V T TA S A N X J U L E I G O KW S N V A T Y I Z L E T K
Eagerly he ran his eye down the columns of letters, as he had become accustomed to doing with the old cipher, but the letters were unintelligible. Next he read the letters across the rows, but with no better result. The eager look faded from his eyes.
"I'll have to try the other," he said, and began to make his letters into rows of five each, thus:
E E A N NR D B O EU N R Y WS E U T TE R O N SN N F E EI A Y W MN V T T AS A N X JU L E I GO K W S NV A T Y IZ L E T K
With renewed eagerness he ran his eye down the first column. "E-R-U-S-E-N-I-N——" he began, then stopped short in disgust. "Nothing doing that way," he muttered.
Then he read the letters across the rows: "E-E-A-N-N——"
"They've got me stopped," he said. And he threw down his pencil and sat staring at the paper before him, twisting the letters into every shape he could think of, but to no avail.
Meantime each of the other members of the patrol was going through much the same process. Lew gave up first, acknowledging himself beaten. Henry sat scowling and working away industriously. Dr. Hardy tried first one combination of letters, then another, but in vain. Willie had laid out the letters in exactly the same way Roy had. But Willie worked differently from any boy in the group. The rest had been feverishly setting down letters as new combinations presented themselves to their minds, whether the combinations seemed logical or not. Willie first arranged his letters in the long rows and sat for many minutes looking intently at them.
At Camp Brady it was Willie who had learned, better than any other member of the patrol, the lesson of observation. When the patrol was practising scouting, which is only another name for close observing, Willie had sat for hours studying the landscapes, even when his fellows teased him. Thus he had learned to see everything within sight and make note of it. And when a guide was needed later, to conduct a party through the midnight woods in quest of the dynamiters' lair, Willie was the scout who was able to do it. He had observed perfectly and so carefully noted what he saw that even in the darkness he could find his way.
So now he examined his long rows of letters until he knew everything about them; and he was certain they told no story. When he was certain, he rearranged the letters, as Roy had done, in rows of five each. Then he laid down his pencil and began another careful search. He read the topmost line from left to right, and from right to left. It made no sense. He took the second and found no meaning in it. Another boy might have skipped the others, but not Willie. Each of the thirteen rows he studied forward and backward.
Then he ran his eye down the first column, just as Roy had done. It spelled nothing. But when he began at the bottom and came upward, an eager light leaped into his eyes. He could make nothing of the lowest five letters; but the eight above certainly spelled two words: "nine sure." If the message was in English, Willie knew he had found something definite to work on. He could make nothing of the second column, either upward or downward. But the third column gave him distinctly the words "twenty four." The next column yielded more words: "Six twenty."
By this time Willie's eyes were flashing. He turned to the bottom of the last column and began to read upward. A single glance confirmed his suspicion.
"Captain Hardy," he cried, jumping over to his chief, and laying his paper on the captain's desk, "begin at the bottom of the last column and read upward. I believe this cipher is exactly the opposite of the other."
Willie's fellows dropped their pencils and gathered eagerly about their leader as he slowly read the letters, beginning at the bottom of the last column and reading upward and backward in the exact opposite of the way the former messages had been deciphered.
"K," he read, "I-N-G-J-A-M-E-S-T-W-E-N-T-Y-S-I-X-T-W-E-N-T-Y-O-N-E-T-W-E-N-T-Y-F-O-U-R-B-A-L-A-K-L-A-V-A-N-R-E-N-D-E-Z-V-O-U-S-N-I-N-E-S-U-R-E."
"Hurrah for Willie!" cried Roy, who had been putting down the letters as Captain Hardy read them off. "He's solved the problem. Who says boys aren't any good? I'll bet you——"
But Roy was interrupted by his mates. "Read it to us," they demanded.
"It's a funny message," said Roy, and slowly he read the following: "King James twenty six twenty one twenty four——" Then he stopped. "I can't read the next words," he said.
Captain Hardy took the paper from Roy and read the entire message. "King James twenty six twenty one twenty four Balaklavan rendezvous nine sure."
"What a queer message," said Henry. "What does it mean?"
"It means," said Captain Hardy, "that the Germans have done their very best to deceive us. They not only changed their cipher, but they sent their message in code. We have read their cipher, but we know no more than we did before. We can never work out their code. All we can do is to guess at the meaning. Our difficulties, instead of being ended, are just beginning. I am more and more convinced that this message is important."
The look of astonishment that appeared on every face at the reading of the message was soon succeeded by one of bewilderment.
"How are we ever going to find out what it means?" demanded Willie. "We can keep juggling letters around until we get them into the proper combinations to make words out of them. But here we've got the words. And they don't mean anything to us. And I don't see how we're ever going to find out what they do mean. We couldn't juggle words around, too, could we, Captain Hardy?"
"No, Willie. There is no use trying that. The spies know what the words mean, all right enough. And nobody else does, unless he has the key to the code. All we can do is to guess what they mean."
"It will take some tall guessing," laughed Roy. "I don't even know what two of those words mean. Read 'em, Willie—those two long ones."
Everybody laughed. "B-A-L-A-K-L-A-V-A-N R-E-N-D-E-Z-V-O-U-S," spelled Willie. "They've got me stopped, too. What do they mean, Captain Hardy?"
"Balaklavan evidently is an adjective referring to Balaklava. Does any one of you remember that word? You've had it in history."
"I know," said Henry. "That's where the Light Brigade made its famous charge in the Crimean War."
"Good," said Captain Hardy. "That's exactly right. So that word evidently refers to a famous battle-ground. Can it be that we have stumbled on a diplomatic message instead of one meant for these spies? Could it be that this message has anything to do with the situation in the Balkans, I wonder?" and Captain Hardy began to turn the matter over in his mind.
"You didn't tell us what that other word meant," said Roy.
"Oh!" said the captain, with a smile. "That's a word of French origin that means meeting-place. Balaklavan meeting-place, Balaklavan meeting-place," repeated the captain. "This certainly must be an important message. The Chief ought to know about it at once. But I wouldn't dare telephone it. I'd have to take it to him."
"Maybewecould find out what it means," said Roy, "if only you would stay to direct us. Wouldn't it be great if the wireless patrol——"
"Roy," interrupted the patrol leader, "I know how you feel. You are very loyal to the wireless patrol. But this is a case that calls for loyalty to Uncle Sam first. The important thing is to get the message read—not to have it read by any particular persons."
"Let me take the message to the Chief," suggested Lew. "I am no good at this sort of thing, but I can carry a message as fast as anybody. Then you could stay here and help the others."
"Very well, Lew. Take a copy of the message as we caught it, and a copy of the cipher as we arranged it. The Chief will learn as much from them as he would from half an hour's talk. Now hurry."
In a few minutes Lew was speeding toward Manhattan with the message in his pocket, while the remainder of the wireless patrol were drawn up about Captain Hardy's desk, in earnest consultation.
"If only we had an up-to-date history," sighed Henry. "Then we'd know who the sovereigns are in the Balkans. All I know are Peter, of Servia, and it seems to me that he abdicated or died; and Ferdinand, of Bulgaria; and Constantine, of Greece, who abdicated in favor of his son Alexander; and the king of Roumania—isn't his name Ferdinand, too?"
"Then there is Charles, of Austria," suggested Captain Hardy, "and the Turkish Sultan, and King Victor Emmanuel III, of Italy. But I can't think of any King James. Well, we'll drop the kings at present and go on with the cipher. That brings us to three groups of letters—twenty-six, twenty-one, twenty-four. I know that code makers frequently use arbitrary groups of letters or figures to represent given words or ideas, but I haven't the slightest notion as to whether these figures belong together or are to be read separately. And as to what they mean, we can only guess. Since they seem to be in connection with some ruler and something about a Balkan meeting-place, they might refer to troops. You don't suppose the Germans are massing forces for another drive into Roumania or that part of Russia around the Black Sea, do you?"
For a little time there was complete silence, as each member of the party struggled to remember all that he had read about the situation in the near East. But none could throw any light on the matter.
"Well, we will drop the numbers and go on," said Captain Hardy. "That brings us back to the Balaklavan rendezvous. The word rendezvous plainly indicates some kind of a meeting. A number of people are going to get together somewhere. If the place indicated were not so evidently in the Crimea, I should think that the message might mean that these German agents we've been watching are summoned to a meeting somewhere."
Again there was a long pause. "Henry," said Captain Hardy suddenly, "to whom was this message sent, and by whom?"
"It had the same call signals that have always been used. It must have been sent from the motor-car station and it is intended for the same station or stations the other messages were sent to. But we don't know yet where they are."
"What would this motor-car driver, Sanders, be sending out a message about the Balkans for?" demanded Henry. "Is he connected with the German diplomatic corps as well as with the spy activities?"
"That's exactly what I was wondering about," replied Captain Hardy. "I can make nothing of it. The only thing I can understand is the last part of the message—'nine sure.' Somebody is to meet somebody somewhere at nine o'clock sure."
"If they meet at the Balaklavan rendez—— What's that word? I can't remember, Captain Hardy," said Roy.
"Rendezvous."
"Well, if somebody is to meet at some place at nine o'clock, the place can't be in the Balkans—not if the people who meet are the persons who received this message."
"You're right, Roy. And they couldn't meet in Europe, or even very far away in the United States, for," he continued, glancing at his watch, "it is already long past luncheon time."
"Well," said Henry, "there wouldn't be any sense in telling these spies about a meeting in the Balkans, anyway. So the message must be intended to call them to a meeting themselves."
"It must be so," assented Captain Hardy. "And if it is so, the situation is serious. Why should they want to meet? And why should the need be so urgent that they can't wait to send their message by safer channels, but fling it out into the air for anybody to pick up and read, if he has brains enough to do it? Hello! Here's Lew back again." And turning to the new member of the group, the leader said, "What did the Chief think of your message?"
"He was as puzzled as we were. He said his cipher experts were as busy as they could be with wireless messages of the utmost importance that the Germans had sent from Brazil to Berlin and that government operators had intercepted. But just as soon as he can get a man who knows anything about ciphers and codes, he will put him at this job."
"Then it's all the more important that we should unravel this thing ourselves. If something is to be done at nine o'clock, we haven't a moment to lose."
Hastily they ate their luncheon, then filed back to their living-room, where lay their maps, books, guides, and other equipment.
"We had better clear off these tables and desks," said Captain Hardy, "so that we shall have plenty of desk room. Suppose you pile these books on that book-shelf there, Henry. And you, Willie, put those maps on the mantel over the fireplace."
Henry gathered up a huge armful of books and hastily dumped them on the book-shelf indicated. They slid down into a heap, but none fell to the floor. Henry, in his usual careful manner, began to set the books to rights.
"Never mind that now," exclaimed Captain Hardy. "That can wait until we have more time."
Willie, meanwhile, was hastily stacking maps on the mantelpiece. He did not bother to fold them up, but put a weight on them and let the sheets hang down toward the floor. In no time the desks were cleared, and the little group soberly seated before them.
"You've taken away the paper with the message on it," said Captain Hardy to Henry.
Henry started for the book-shelves, but Willie, who sat nearest the shelves, was there almost before Henry was out of his chair. He scanned the heap of books, looking for the missing paper.
"There it is, under that Bible," he muttered.
He lifted off the superimposed books, and shoved the Bible to one side. The books began to slide, but Willie stopped them before they poured down to the floor. The Bible he caught on the very edge of the shelf, its covers open. He thrust the book back, seized the paper, and returned to his seat.
For perhaps an hour the little group worked on. Sometimes each labored in silence, busy with his own thoughts. Again there was eager discussion, as one or the other advanced some theory or idea as to the meaning of the message. Then silence would come again. So the hours rolled by. In one of these pauses, Willie sat with closed eyes, turning the mystery over in his mind. But his brain was tired and other thoughts would creep in. Once he caught himself thinking of Camp Brady. Again he was thinking about the East River, and all the sights he had seen on a trip he had made up that stream into the Sound. Rigidly he brought himself back to his task. But presently his attention wandered again. Now he was thinking about the book-shelf and the volume he had caught as it was slipping to the floor. And then, as though a flash of lightning had suddenly illuminated a dark place in his brain, he saw the words on the open page of the book—words that in his haste he had barely glimpsed, but that now came vividly to his mind:
In another instant Willie was on his feet. "There's one King James that we didn't think of," he said, "the King James of the Bible."
His fellows laughed. "He's dead," said Roy.
But Willie paid no attention to the comment. His look was centred on his captain's face. And his captain's face was worth watching. Over it came that eager look that always marked his countenance when he got new light on a problem.
"Willie," he said, "I can't see the connection offhand, but it may well be that there is one. Can anybody think of any connection between King James and Balaklava and these spies?"
Nobody could. "The only thing that King James is remembered for," continued Captain Hardy, "is this very Bible—the King James' version, as we call it, in contradistinction to the Revised version. But I don't quite see how we can connect him with the rest of the message. Read the message over again, Henry."
When Henry had read it, Roy said, "If it said Matthew, or Psalms instead of King James, you would think that it was a text."
Captain Hardy leaped to his feet. "Stupid!" he cried. "Why didn't I see it before? Of course it's a text. Bring me the Bible. King James, 26, 21, 24," muttered Captain Hardy, as Roy placed it before him. "That must indicate the book, chapter, and verse."
He turned to the table of contents and began to count the books of the Bible. "Ezekiel," he announced, when he reached twenty-six. "If our theory is correct, this message refers to Ezekiel 21, 24. We'll soon know whether we're right or not."
His fingers trembled as he turned the pages, so eager was he. He found Ezekiel, turned to the twenty-first chapter, and ran his shaking finger down the columns until it rested on the twenty-fourth verse.
"Listen," he said, and his companions scarcely breathed as he read: "'Therefore thus saith the Lord God, Because ye have made your iniquity to be remembered, in that your transgressions are discovered, so that in all your doings your sins do appear; because, I say, that ye are come to remembrance, ye shall be taken with the hand.'"
For an instant complete silence followed the reading. Then Captain Hardy said, "Willie, you've solved the riddle. And it is just as I feared. The Germans have been alarmed. They know that they are detected. Now everything is plain enough—in a way. They had to warn all the members of the gang and they hadn't time to send messages. So they took a chance on the wireless. But they used a new cipher and resorted to a code. The use of the word 'rendezvous' indicates to my mind that they intend to flee. They're going to meet at the 'Balaklavan rendezvous' at nine. We've got to find where that is and get the secret service men there in time to nab them. And the afternoon's almost gone already."
Captain Hardy pulled out his watch and groaned as he looked at it. "We've got to watch these spies, too," he said. "Above all things we mustn't let them get away from us. If we can't find out where the Balaklavan rendezvous is any other way, we can trail these fellows to it."
Then the leader of the scouts turned to Lew. "Hustle down to the pine tree," he directed, "and watch the hawk's nest. It may already be too late. But if anybody is still there and comes out, trail him no matter where he goes. You can get into touch with me by telephone. Meantime, I'll communicate with the Chief."
Lew hurried away and Captain Hardy left the room to telephone. He came back with a white face.
"The Chief hasn't a man available," he reported. "All his men are watching some plotters who are trying to burn grain elevators and fire shipping. He says it's up to us and the police. So I called Police Headquarters and two detectives will be sent here at once. Pray Heaven they come in time."
Hardly had he finished speaking before Lew burst into the room. "Captain Hardy," he cried, "I was too late. Just as I reached the pine grove, I saw the spy running down the slope. He was a quarter of a mile away. I ran after him. But before I got near the shore he stepped into a motor-boat that was waiting and away he went. There were three other persons in the boat, and I am sure one was the grocer and one his boy. I had no way of following them, so I came straight back."
Just then the door-bell rang. Their hostess announced two men to see Captain Hardy. And the two detectives entered.
"Too late," groaned Captain Hardy. "The birds have flown. And we do not know where they have gone."