It was Jack who sounded a signal on the auto whistle for the other craft to lay to.  Then Benson steered in closer, the two who had been rescued standing not far from him on the platform deck.  The older man still clutched his satchel.

“Submarine, ahoy!” came a hail from the schooner’s deck.  “Is that you, Mr. Miller?”

“Ye-es,” hesitatingly admitted the older man, at which Jacob Farnum smiled grimly, though he said nothing.  “Put off a boat and send it alongside, will you?”

In a trice a boat was lowered from the schooner.  Manned by two sailors and steered by a deck officer, the boat came alongside the sloping hull of the torpedo boat.

“You weren’t expected in such a craft as this, Mr. Miller,” called the deck officer in the stern of the small boat, touching his cap.

“Never mind any conversation, my man,” broke in young Miller, testily.  “Lay right alongside, and help get my father into your boat.”

Hal and Eph helped in piloting Mr. Miller over the side and getting him into the boat alongside.  Immediately afterwards the younger man jumped into the small boat.

“Oh, you’re going with your father, are you?” hailed Mr. Farnum.

“Yes,” replied the son, coolly, though with another scowl.  “A thousand thanks for your kindness to us.  Good-bye!”

The small boat put off, making rapidly for the schooner.

“Well, full speed ahead for Dunhaven,” muttered Jacob Farnum.  “But that’s the queerest crowd I ever ran into.  It’s uncanny, all the way through.  Somehow, I can’t shake off the impression that I’ve been engaged in some stealthy or nasty work.”

The run back to port was without incident, the submarine behaving perfectly on the surface.  Indeed, all aboard were highly delighted with the new boat.  Jack was still at the wheel as they glided into the little harbor.  Anchor was dropped and power shut off for the night.

“You three boys may as well stay aboard for the night,” suggested Mr. Farnum, as the night watchman of the yard appeared, coming out in a row-boat.  “In fact, you may as well live aboard, and use the pantry and galley for all your meals.”

“Shall we keep watch through the night, sir?” asked Jack.

“No need.  Let the yard watchman do that.  It isn’t far from daylight.  Get yourselves some coffee in the galley, have a good rub-down, spread your clothing to dry, and turn in in the state-rooms.”

Grant Andrews went ashore with the builder and the inventor.  The first thing the submarine boys did was to start coffee in the galley.  Next they rubbed down, got into dry underclothing, then sat down over their coffee.

For some minutes they discussed the mystery of the night, making all manner of guesses.  At last, however, they lay down in the berths of the state-rooms, and were soon sound asleep.

Nor did any of them wake until Jack opened his eyes in the forenoon, when he heard someone coming down the spiral stairway.