“But who could have let a torpedo loose in that fashion?” stammered Farnum.  “What accident—­”

“Accident!” broke in Jack, sneeringly.

“Accident!” repeated Danvers, scornfully.

“Well, then, how—­”

“Mr. Farnum,” broke in Jack Benson, sternly, “that torpedo was fired by design, with intent to sink us!”

“What?  Who—­”

“I can’t make any positive charge,” it was Lieutenant Danvers’s turn to say.  “But I can offer certain evidence that I’ll stick to anywhere.  Just a few seconds before that torpedo got so close to us I was noting the Rhinds boat, the ‘Thor.’  Her course was toward us, briefly.  Then she turned off on another course.”

“Do you mean to say that the Rhinds boat was turned our way at just the time when that torpedo could have left her, headed for us?” demanded Jacob Farnum.

“That’s the whole indication,” replied Lieutenant Danvers, firmly.

“Then what are we doing, waiting here?” cried the shipbuilder, angrily.  “Jack, now that that torpedo is spent, and lying harmless on the water, start up speed and head over that way.  Go carefully, for, remember, any sudden shock against the war-head of the torpedo would set it off.”

Jack signaled for slow speed ahead, the response coming promptly.

“Somers,” directed Lieutenant Danvers, “get the signal bunting out, and I’ll help you rig a signal to the ‘Oakland.’”

It was the first time, on any of the cruises, that Danvers had attempted to give an order, or to take any part in the handling of the craft.  But now he was about to make a serious report, as an officer of the United States Navy.

In a very few moments, Danvers and Somers working together, the necessary flags were out, and knotted to the line in their proper order.

“Hoist away!” ordered the lieutenant, himself giving a hand on the halliard.

Up the signal mast went the line of bunting, fluttering.  The little flags spelled out this message to the gunboat: 

“Evidence of serious foul play.  Join us to investigate.”

Almost immediately there came a signal from the bridge of the gunboat, to show that the message had been read.

Jack was now slowing down speed, making ready to lie to, a hundred yards or less from the floating torpedo.

“Mr. Farnum, Hal’s always at his post,” said Jack, “but call down to him to be sure to stick particularly close for the next few minutes.  If the wind shifts, and heads that torpedo our way, I want to be sure of instant speed for getting out of the way.”

The gunboat was now cruising leisurely over to where the “Hastings” waited.  Danvers signed to the officer on the “Oakland’s” bridge to keep an especial eye on the floating torpedo.

As the “Oakland” slowed up, a cutter, in charge of an ensign, put away from the gunboat’s side.

“Ensign,” shouted Lieutenant Danvers, “we shall feel obliged if you can lie alongside of that torpedo, and render the war-head harmless.  We believe the torpedo to be fully loaded, and ready for instant action.”