"Don't try any such game as that or there'll be trouble, you young cub," the man whispered, and almost before Jet knew what was being done a hard substance had been forced into his mouth and fastened there by a towel tied around his head.
That he was a victim of foul play the young messenger could have no doubt, and he struggled with all his strength to free himself, but in vain.
The stranger took from his pocket several lengths of stout rope, bound first Jet's hands and then his feet, after which he threw him roughly into one of the berths.
"I reckon you'll lay there without making very much fuss, till I get ready to let you go," he said, as he treated himself to a long draught from a black flask. "When we do land at Yonkers, you can go back to Police Headquarters once more."
The latter remark caused Jet to associate this adventure with the one he had had in the morning, and after looking intently at the stranger his suspicions became a certainty.
"This is the short fellow who got me to carry the valise!" he said to himself. "They know about my goin' to see the inspector, and are bound to get me out of the way."
The idea that his captor was a cold-blooded murderer, who probably would not hesitate to add another to his list of crimes, was far from reassuring, and the perspiration burst out on Jet's face as he thus persuaded himself he was in immediate danger of a violent death.