“This is treachery!” stormed the prisoner.  “I didn’t surrender to you.  I only came out to talk with you.”

“If you didn’t surrender, then excuse me, and go ahead and put up a fight,” laughed the policeman, handily removing Evarts’s revolver from a hip pocket.

“Now, look in here, Tom,” urged Dick.  “Do you see what caught my eye?”

Prescott pointed to a sharp-nosed cylinder, some eight feet long.  Just as it lay the propeller at the other end was invisible to one at the doorway of the cabin.

“It’s a home-made imitation of a Whitehead torpedo,” Lieutenant Dick went on, in explanation.  “If it proves to be charged with explosives then the mere having of it aboard this sloop will prove embarrassing to these two prisoners to explain in court.  If it isn’t loaded, that will be almost as bad, as such a torpedo can be rather easily loaded, and then set in operation by clock-work machinery that will control the propeller.”

“Young man, you seem to think you know a good deal about torpedoes,” sneered Evarts.

“He ought to,” Harry retorted quietly.  “He’s a West Point man and an army officer.  Therefore, he’s a specialist in some kinds of explosives.”

Evarts’s face turned somewhat paler at this information of having an army officer on hand as a witness.

“Do you call me a prisoner, too?” asked the man at the tiller uneasily.

“Something like it, I guess,” nodded Dick.

“Say, but that’s a pretty rank deal against an honest man,” protested the skipper hoarsely.  “I hired this boat out to that man, the one you call Evarts, but I didn’t know what he was up to.”

“You didn’t know that torpedoes are used for wicked work either, eh?” pressed Lieutenant Dick.

“I’ll swear that I didn’t know what it was that he brought on board,” cried the skipper.  “Evarts said it was a new device for killing fish at wholesale.”

“You may be telling the truth,” Tom broke in.

“I am,” declared the skipper eagerly.

“Then explain it to the court,” Reade continued.  “If you can prove to a judge and a jury that you’re an honest man, and always have been one, you may get off on the charge that will be made against you.”

“Then you don’t believe me?” asked the skipper anxiously.

“It isn’t for me to say,” Tom replied crisply.  “It’s a job for a judge and a jury.”

“Then I’m to be a prisoner?”

“That’s for the policeman here to say.”

“You’re a prisoner, my man,” nodded the policeman.  “Now, sail your boat into the landing over yonder.”

“Some one else will sail it,” retorted the skipper, angrily, as he abandoned his tiller.

“I’ll take the tiller,” Harry suggested, and did so.  He hauled in the sheet, brought the boat around and headed for the landing with the skill of an old sailor.

“My man, since you don’t want to sail the boat you’ll have to go as a real prisoner,” announced the policeman.  He produced a pair of handcuffs, snapping them over the man’s wrists.