Jack Benson and Hal Hastings heard, but did not change color.  There was no sense in losing nerve over a disaster that had been averted in time.

“The first thing to do, of course,” continued Lieutenant Commander Kimball, “is to send instant word to Messrs. Trotter and Packwood.  They have a heap of work ahead of them.”

“As to our own boat’s crew,” replied Jack, “I fancy the best thing we can do is to go back on board, since we can’t do anything here.  One of us will keep watch, and the rest of us can get some of a night’s sleep yet.”

“Why, yes, if you youngsters can sleep, after such happenings,” laughed Kimball.

By this time Lieutenant Foster and two of his marines had followed the trail of footprints as far as the hard road.  Here all trace was lost.

“What you want to do, Williamson,” declared Jack, as soon as the submarine people were back on their own craft, “is to get into some dry clothes and make yourself a pot of hot coffee.  Then get in between blankets for a sleep.  I’ll finish out your watch.”

Nor was Benson alone in his watch, for a cutter from the gunboat, containing a corporal and two marines, beside sailors to row the boat, moved slowly around the submarine at a distance of fifteen or twenty yards.

After the rest had gone below, Captain Jack, hanging over the rail of the platform deck, saw other lanterns gleaming in and around the clump of bushes.

“That must be the Secret Service people, pulled out of their comfortable beds,” mused Benson, smiling.  “Won’t they feel upset at any such thing happening hours after they’ve arrived on the spot?”

After Eph Somers had reported on deck to take his watch, Jack went below, once more dropping into sound slumber.  The smell of coffee and bacon was wafted in from the galley when the young submarine captain next awoke.

“Well,” announced Eph, as Jack and Hal came forward for their breakfast, “Trotter and Packwood haven’t caught the fellows that laid the mine.”

“It doesn’t look strongly probable that they’ll catch them, either,” Jack replied.  “I don’t believe that the fellows who did that trick are any of the regular spies.  For that matter, we now of only three spies here who are men.  Drummond is under arrest, and so is Gaston.  Neither of them could have had a hand in it.  And there were two, so, if M. Lemaire was in it, he had an unknown accomplice.  But I don’t believe M. Lemaire had any personal hand in laying that mine.  I’ve a notion that he considers himself entirely too high class to go into any mere blasting operations.”

“‘Mere blasting operations’ is good,” smiled Hal Hastings, “when we stop to think what those ‘blasting operations’ might have done for us if it hadn’t been for Williamson.”

“Anyone taking my name in vain?” demanded the machinist, smiling as he put in an appearance at that moment.

“We’re trying to see,” Eph explained, “whether we can do any better guessing than the Secret Service men as to the fellows who were kind enough to lay that mine under us last night.”