"Evarts, this is mighty mysterious!" groaned the young chief.

"Unless---" hinted the foreman.

"Unless what?"

"Perhaps Mr. Hazelton ran along the walltop to the sh.o.r.e."

"He'd have hailed us, then, in pa.s.sing, wouldn't he?" choked Tom Reade.

"Besides, I had the light playing on this wall most of the way. If he had run back we would have seen him, even if he hadn't hailed. And he couldn't have run farther out to seaward. Evarts, I'm downright worried."

Tom Reade might indeed well be worried over the grewsome mysteries of this night of evil deeds.

CHAPTER IV

SOME ONE CALLS AGAIN

Half an hour later Tom Reade leaped ash.o.r.e at the little pier.

"My orders, Mr. Reade."

"They're brief and concise," Tom rejoined. "You're to cruise the length of the wall, especially farther out from sh.o.r.e. Use your searchlight freely. Keep the wall so guarded that no rascal can slip out there, either over the wall or by boat, and do any damage. Mr. Evarts, the safety of the wall until daylight is your whole charge."

"Very good, sir. But I'm sure that nothing more will happen to the wall."

"If anything does it will be up to you, Mr. Evarts," Tom a.s.sured him grimly. "I'll hold you responsible."

"I won't let anything happen, Mr. Reade. And I hope you find Mr. Hazelton all right."

"He may be up at camp," Tom answered, though in his heart he did not believe it.

Had Harry escaped whatever danger had menaced him, Tom knew very well that his chum, after appealing for help, would by some means have signaled his subsequent safety.

However, Tom started toward camp at a run. He was wholly mystified. The search in the neighborhood of the breach in the wall had been continued until its hopelessness had been fully demonstrated. The search had also been continued over the water, for a possible clue to the mystery.

Though Tom ran, he felt himself choking, stifling. Despite all his efforts to cheer himself the young chief engineer felt certain that his chum had mysteriously met his fate, and that brave, dependable Harry Hazelton was no more.

Yet how could he have vanished so completely, and what possibly could have happened to his a.s.sailant or a.s.sailants?

"It'll be an awful night, until daylight," Tom groaned inwardly, as he ran. "At daylight, of course, we can make a far better search, especially over the water. But in the hours that must elapse---! It's going to be a tough period of waiting!"

Arrived at camp, Tom made straight for his own barracks, letting himself in with a latch-key as soon as he could control his shaking hand sufficiently to use the key.

Tom bounded straight for the bed-room of the superintendent, at the rear of the little building.

"Mr. Renshaw!" shouted the young chief, throwing open the bed-room door.

The barrack was lighted by electricity. Tom threw on the light, then wheeled toward the bed, to find the superintendent sitting up, revolver in hand.

"Oh, it's you, is it?" gasped the superintendent. "Mr. Reade, in my stupor from being aroused I was just on the point of shooting you for a burglar. It's awful!"

"You ought to throw that revolver to the bottom of the gulf," Tom rasped out.

"Not much!" retorted the superintendent. "Handling as mixed a crew as we have on this work I wouldn't think of going about unarmed. And you ought to go armed, too, Mr. Reade."

"Bosh!" uttered Tom. He had a well-known objection to carrying a pistol.

Reade always maintained that a pistol-carrying man was a coward. A coward is one who is afraid, and the man who is not afraid has no reason to carry a weapon.

"Renshaw," added Tom, "there's just one circ.u.mstance in which I would carry a pistol---and that is, if I were carrying large sums of other people's money. If I were a pay-master, or a bank messenger, I'd carry a pistol, but under no other circ.u.mstances, outside of military service, would I carry a weapon. But---are you thoroughly awake, now?"

"Yes, sir."

"Then, Mr. Renshaw, get up and hide that pistol somewhere. While you're about it, listen to me. Some scoundrel has blown out a large portion of our retaining wall to-night. I left Hazelton on guard at the point and came ash.o.r.e to get out the motor boat, 'Morton.' Before I could return I heard Hazelton's call for help, and---he has disappeared! There's wicked work on hand to-night. You'll have to get up and help me. Be quick with your dressing. We've work to do to-night, and all of it is man's work."

Tom hastily added such other particulars as were needed. Renshaw, while he dressed hurriedly, listened with a horror that he took no pains to conceal.

"Evarts claims that it's revenge work, on the part of some of our men, because Hazelton and I stopped gambling in the camp," Tom continued.

"It might be," Renshaw admitted thoughtfully. "But to me it seems that there must be a lot more behind the whole terrible matter."

"That's the way it strikes me, too," Tom nodded. "However, you're dressed, so now we can hurry out and get busy."

"What shall we do first?" Superintendent Renshaw inquired.

"That's what I've been thinking over while you were dressing," Tom replied.

"Of course the one thing of real importance is to find Hazelton."

"Killed, beyond a doubt," replied the older man.

"I refuse to believe it," Tom retorted. "There's a mystery in his fate, but I simply won't believe that Harry has been killed."

"Then why didn't you hear from him further?"

"That's the mystery."

Tom had shaped their course for the barracks occupied by the foremen. He bounded upon the little porch and began to hammer on the door with both fists.

"Turn out, everybody!" Tom bellowed. "Every foreman is on duty to-night.

Show a light, and let us in as soon as you can."

Some one was heard stirring. Then Dill, one of the foremen, admitted the callers.

"Are all the others up?" Reade asked, sharply.

"Yes, sir."