"That's a good one on you, son," laughed the latter's father. "I thought you were the highbrow of your bunch; but here's our subtle Tee-hee putting a bit of clever phraseology over on you."
"Oh, I know what he means," Cub rejoined with a panicky haste to recover lost prestige. "I was just giving him a dig. He's forever giving me one, whenever I come along with anything of that kind."
"It indicates that his mind is maturing rapidly," said Mr. Perry. "All right, Hal, we'll accept this island as a center of probability—what next?"
"Why, let's cruise around about half a mile in all directions and pick out those islands that look as if they might have concealed a prisoner from view of passing boats."
"That's a good suggestion," said Mr. Perry. "Bob, start the boat again."
The inspection required about an hour, at the end of which they compared notes and found that their island inventory disclosed the following conditions:
Three possible places of concealment for the "Canadian Crusoe" had been discovered. Two were small islands a short distance from each other in a region of shallows and more or less hidden by rows of long slim islands. No boat of greater draught than a canoe could make its way through the intervening passages. In other words, these islands were virtually isolated from all river traffic. The other possible place of concealment was an island about five acres in extent, completely hemmed in by a group of other islands, which were so overrun with rampant vegetation, including bushes and trees, as to conceal the inner isle from any but the most scrutinizing vision.
"That is the place we want to explore first," announced Mr. Perry as reference was made to this retreat in the check-up.
"I agree with you," Bud declared. "If the prisoner left any traces behind him at all, we're likely to find them on that island in there."
"Is there any way we can get in?" Hal inquired. "Too bad we haven't a small rowboat or canoe with us."