As there was no reason for lingering in the vicinity, the Huron, soon after, was put under full speed, and under her powerful engines she passed through the straits before sundown.
Supper was eaten, and Tom once more emerged on deck before the after-glow had faded. He gazed about him abstractedly. The lad was sorely troubled. Now that the excitement of the novel trip on the submarine had worn off, thoughts of his brother's plight and of Sandy's misfortune came back to him with redoubled force.
All at once—to the westward—a dark cloud appeared against the glowing sky.
"Smoke!" decided Tom. "Some craft coming this way."
For half an hour or more he watched till the outlines of a tug appeared from the direction in which he had first noticed the column of vapor.
Tom watched her without especial interest for a time, and then the blood began rushing through his pulses in leaps and bounds. He bounded to his feet and rushed to the conning tower. Thrusting his head over the hatchway, he gave a shout that electrified those below.
"Captain Rangler's tug is dead ahead and coming toward us!" he announced.
CHAPTER XVIII.
A MAN OF QUEER MANNERS.
At just about the same moment that the submarine encountered the sunken wreck, Jack Dacre, as well as Sandy MacTavish, was sucked into the black and treacherous slime of the slough. As our readers will recall, we left both lads in about as bad a situation as could be imagined.