Seemingly unaware that Chick dogged his steps, the control room chief, whose initials, J. V., had proved the baffling tracing to be his property, went from the runways to his tower quarters.

Doc Morgan, following Chick, appeared at the door to the control room a minute after the youth had seated himself unobtrusively, in a chair in a dark corner.

“You might as well go home,” the control room chief dismissed his assistant who turned from an observation window where he had stood scanning the sky, and taking his hat, said “Goodnight.” His chief, paying no attention to Doc as the latter lounged in the doorway, walked to the windows and glanced in several directions towards the heavens.

Chick sat quite still. Doc knew he was there, he saw; but Doc was evidently interested in his own thoughts, and, beyond giving Chick a pleasant wink, ignored his presence.

Vance, the control chief, assured himself that there was no immediate need for his services for landing ships. He adjusted several switches to leave the essential lighting of approaches going against Don’s return, and then walked over to the radio table in one corner.

Chick, watching, saw that the man’s thoughts were far away from duty.

Watching unobtrusively, he saw Vance lean his head on the hand supported by an elbow on the table.

Doc, still lounging, seemed forgotten, and appeared to be satisfied.

“They are both thinking about the same thing. That’s my guess,” Chick told himself. “Doc had something to do with that tracing that turned up in a boathouse in the marsh, and Mr. Vance knows it. And Doc knows he knows it, too! I’ll sit tight and see what happens.”

He had no long vigil.

Apparently so deep in his thoughts that he forgot the others, Vance sat in a brown study for a moment: Chick, quick of eye, observed that the control chief was not so oblivious as he pretended.

“He’s watching Doc,” he decided.

The silence was broken by Doc’s amused voice.

“Well, J. V., go ahead and unlock the drawer. You want to, you do, and you know it, you do that! Well, go on. Do it! I’d like to know what that sketch means, I would. Let’s see it again, eh?”

With a start of surprise that Chick sensed as “acting,” the other looked around quickly.

“Oh! Hello! What’s that, Doc?”

“You heard me.”

“About the tracing, it was.”

“Yep.”

“Rats!” The man leaned back, arms behind his head, carelessly locking his fingers as he pretended to laugh. “Doc, you’re pretty interested in that, aren’t you? Considering where it was found——”

“Yes, considering where it was found—” Doc repeated the words with a meaning that differed from the other man’s phrase. “Considering that it was supposed to be a sketch of a new design for an airplane, and I saw our young friend, Chick, discover it when the wind yanked it out of a drawer—” he forgot his mannerism and spoke directly, crisply, “I wonder if you go over there to work on it in secret—eh?”

The man swung around in his chair.

“As likely as that you go there to hunt sea-marsh stuff for medicine,” he snapped. “It was stolen from me, as a matter of fact!” He turned his eyes on Doc, accusingly.

“Not by me, brother not by me, not it! No, sir! You got it back, anyhow, so what’s the odds how it went? What is it—besides a sketch of a new aircraft?”

Chick became more alert, more intent: he had to hold in check his impulse to hitch forward in his chair. The answer might be interesting.

The control chief laughed.

“Besides a drawing of an airplane—what could it be, I wonder?”

“Look here!” Doc left the doorsill that had supported him, and took a few steps closer to the other man.

“See here,” he repeated, “do you recollect when the engineers were draining the swamp, and found a skeleton of some poor old codger who was supposed to be one of the old pirate band that used to hang around New York, a good many dozen years ago?”

Chick started. A pirate! He recalled that the local newspapers had printed several lines of historical fact, hinting that the bones found in the swamp might have been a relic of days of piracy in the harbors and bays, the sea and the Sound, in and around Long Island and New York.

Suddenly something that had never before seemed of importance to him flashed across the youth’s agile mind.

Among the piratical names important in history of activity under the skull and cross-bones, none had stood out more than that of Morgan.

And before him stood a man whose name was “Doc” Morgan!

He suppressed his tendency to utter a cry of surprise at his discovery; his ears became even more intent as he held his voice and his quivering nerves in check.

“Oh, yes, I do recall something about the skeleton and piracy,” the control chief remarked, carelessly.

“Well, now, you do, do you? Is that so?” Doc’s tone was sarcastic. “Do you happen to recall that pirates used to sail in brigantines, and such-like ships? Yes, you do! Sure, you do! And there is a story to the effect that one time an old brigantine was throwed up onto the mud, it was, in a gale, off the very swamp where that skeleton was found!”

“You don’t say!”

“I do say!”

The control chief was obviously interested.

“How do you know?”

“Who would know better than a Morgan?”

Chick’s wriggle of excitement went unobserved.

“That’s so,” Vance remarked. “You are named the same as one of the old buccaneers, at that! Say, Doc—tell you the facts:

“I was with the engineers when they discovered that skeleton.”

“I knew it all the time. So was I.”

“Oh, yes—I recollect, you were,” Vance agreed, while Chick listened and tried to register in his memory every look, every phrase, every intonation of the two men. There was either a fresh mystery leaping to the fore, or the explanation of many mysteries was about to come into the light.

“Well—” Doc paused significantly.

Vance cried that he did not understand that hint.

“If you mean that anything was found, you know as well as I do that nothing was,” he finished.

“No,” Doc argued, coming closer, but no longer sarcastic. “No, Vance, nothing was found. But the finding of that skeleton, it brought out all that about the pirates, it did. Yes, sir, it did that! And what’s to say all the talk about the pirates didn’t show somebody—who—already—had a—map-or chart—that it meant something!”

“Let’s see it!”

Chick, forgetting the mission he was detailed to pursue, forgetting his former suspicions of Doc or of Vance, and intent only on that new topic—a mysterious, concealed map or chart, hidden among the intricate lines of a design supposed to be for an airplane, startled the two men by his exclamation.

Vance, wheeling, studied him a moment, evidently becoming satisfied that Chick’s interest was as purely on account of the new idea as was his own or that of Doc.

“Why, sure! You’ve seen it, already, anyhow,” the control chief conceded. “Tell the truth, you two, I can’t make any more of it than you did. The day that the skeleton was found, after you had all gone away, one of the engineers took me to one side, and said he had seen a queer thing when he was in the old boathouse trying to hire a dory, to get to the place where the skeleton had been discovered, and where all the excitement was centered. He had seen a half open drawer in the table there at the boathouse, and in it was a tracing paper, pretty old, and seeming to be of an airplane. It was so curious to see it there that he mentioned it and I took him in our power launch—the crash boat—to the scene of the excitement, and then cruised back to the boathouse for a look at that tracing. It was just what you’ve seen. Well, I sat there, all alone, studying it, but I couldn’t make anything out of it.”

He turned and began sorting keys on a bunch he drew from his trousers as he prepared to open the drawer of the radio table.

“At first I thought what Chick did when he first saw it. There was part of an aircraft series, stolen or mislaid and carried there by some visitor.”

“Then what did you think, afterward!” Chick asked eagerly.

“I wondered, but I didn’t actually decide much of anything,” Vance answered. “Well, you know how a fellow does when he’s absentminded, studying, or something—draws marks on paper!”

“Yes! I’ve seen you do that when you were in a brown study,” Chick agreed. “You draw—let’s see—J. V.”

“Exactly what I do!” Vance agreed. “Well, you two, believe it or not, while I sat there, thinking, I drew my initials on the table, and one set got on the corner of the tracing. I didn’t see how it mattered, and I meant to bring the thing here anyhow. So I let them stand.”

“But you left it there,” contended Doc, “left it, you did. Yet you claimed it, you did so, as yours!”

“Yes. I dropped it in the drawer when a hail came for me to bring the crash launch to help my boss. I wasn’t control chief then, only an engineer working out angles and distances across the swamp for the airport extension,” Vance declared. “I forgot all about the tracing until I read in the papers about the piracy and the hints about lost treasure and all that folderol. Then, when Chick so kindly brought in the tracing, I recollected my initials—and there you are.”

Chick reserved his opinion about the truth and reasonableness of the explanation. Certainly it was a point in Vance’s favor that he was already willingly slipping a key into the table drawer.

“Why!—look here!” Vance cried, “this drawer isn’t—locked!”

He dragged it open. At once Chick knew, just as he saw that Doc realized, that the tracing was gone.

Had Vance made up all that story? Had someone picked the lock? Was that queerly disguised tracery of lines more than an airplane design? Who had it?

Chick took no time to puzzle out answers.

“Never mind, for now!” he exclaimed. “I wasn’t such a dummy, after all. While I had that tracing, before it got lost again I decided to make a blue-print of it. I did, too!”

“Good!” exclaimed Vance, and Doc nodded. “Get it!” he urged.

Chick ran down the tower stairs. At their lower steps he stopped, stricken by an uneasy realization that he had completely shirked the duties laid on him by Don. He was not guarding that tower, not seeing what Vance did, not heeding Doc.

Thirteen years—piracy—mysterious maps—hidden meanings—possibly buried treasure—the combination had been too much for Chick.

Should he go back, or go on and get the blue-print?

“I’d better go back,” he said. “I can get the blue-print when the rest are here. Maybe Vance made all that up, and took advantage of what I said, just to get me off the scent, to stop me thinking about watching him. I’ll go back.”

He turned to ascend.

From the hangars came the crash of an overturned chair, or some such odd sound. On the office floor it seemed to be to Chick.

Furiously racing along the corridor, he watched for opened doors, in the faint light of the corridor bulb at the landing.

The design room door stood ajar!

There he swung in, catching the jamb with a hand to expedite his turn as he reached the opening.

Inside all was dark, still.

“Who’s there?” he called, and listening, heard no sound.

His fingers found the light switch. The room sprang into brightness.

“There’s a chair upset,” Chick called out. “I know you’re in here. Come out!”

Silence met his demand.

With quiet feet he advanced, past an overturned wastebasket, past the filing cabinets. They had been tampered with—he saw that as he passed.

In a corner was a wash basin, marble, on a stand, and before it was a Japanese screen to conceal those who chose to wash.

Tiptoeing, Chick advanced close to the screen.

Unexpectedly it was thrust over onto him. He had half expected the maneuver, and he leaped sidewise and backward, just escaping the edge of the light frame and the entangling silk stretched over it.

A tall, thin, dark-haired, reddish, copper-colored youth leaped past him. Caught off balance, it took Chick half a second to right himself. Then he was in pursuit, screaming as he ran. The other was fleeter, longer-legged. He seemed to have prepared a plan. Chick heard feet on the tower stairway, thudding down to his summons. They might intercept the escaping youth—an Indian, Chick felt assured at that. He was the faster of the pair, and Chick, for all his best effort, could not get a grip on the flying coat.

The Indian swerved, in the hall, into an office. Chick thought he had him cornered until the slam of intervening doors told that his adversary of the design room screen episode was out through the intersecting office suite, and had beaten him.

Chick ran to the fire escape at a window.

Down its iron rungs he went swiftly.

A figure, running lightly, crossed the hangar apron of cement, got to a car. Chick, putting every ounce of energy into his effort, ran, after a leap from the fire escape ladder, to try and reach the car.

“This way—he’s going away in a car!” Chick shouted, to guide the men from the control room.

Then he saved his breath, his task being to get to the car before the youth could get in. It was a light, cheap make of sedan.

Something Garry had told him seemed to come uppermost in Chick’s mind, some recollection; but he was too excited to pause and make sense of it.

The motor roared, gears ground into mesh, the car started.

Chick’s clutching fingers barely missed the rear tire.

He fell, carried forward by his leap, and lay, prostrate.

Then he lifted his head as the car roared away, and when Doc Morgan and Vance reached him, he sat up, smiling.

“Let’s take my car!” cried Vance. “Come on, Chick. Doc, stay and take care of the place. Get my assistant back to the control room!”

“Yes!” urged Chick, running toward the control chief’s bigger, faster roadster, “I remember something. Garry was taken to an Indian camp in that very car, and the very fellow who’s getting away with blue-prints or tracing is the Indian’s son who drove Garry back. I know the license, too. Come on!”