“Just this. I think that La Rue and his companions, after they stole the old man’s boat, made for some rendezvous of the gang. They are there now, according to my best judgment.”

“Yes; that’s about right,” agreed Jennings. “But they’ll make a break as soon as possible.”

“Just my idea, Jennings,” rejoined his chief; “and that ‘break’ will be made on that fly-by-night boat of theirs. They’ll try and dispose of the gems, smuggle them across the line, that is, in some other point along the river; or they may even try to get to the Great Lakes. It’s our job to head them off.”

“A man’s-size job,” muttered Adams.

“All of that,” said the inspector; “that is the reason why I asked this young man for the loan of his boat. My idea is, first to descend on Windmill Island, which, from Master Stetson’s story, I believe to be the hiding place of the gang. The old island would make an ideal hang-out for them. It is full of passages and galleries and then, too, that old windmill tower would make a fine meeting place for such scamps. Folks around here believe it is haunted and wouldn’t be likely to bother them. Young men, we will start for Windmill Island at dusk.”

“You want us along?” asked Ralph delightedly.

“Why, of course,” was the astonished reply. “You didn’t think we could get along without you, did you?”

“Well, I must say that I’d like to be in at the finish,” rejoined Ralph.

“Same here,” put in Harry Ware.

“Me for that cruise, if I never take another,” grinned Percy Simmons delightedly.