Sam and Tom were glad enough to rest awhile before venturing into the
water. As my old readers know, the stream was a swiftly-flowing one,
and the water was rather cool.

"Remember the day we flew over this way in the biplane?" said Tom.
"That sure was some adventure!"

"Yes, but it wasn't a patch to the adventure we had when the biplane
was wrecked," returned his brother, referring to a happening which has
been related in detail in "The Rover Boys in New York."

Having rested awhile, the two boys started to get ready for their
swim. Both had just thrown off their coats, when there came a sudden
cry from up the river.

"What's that, Tom?" questioned Sam.

"Somebody is calling. Listen!" and then both boys strained their ears
for what might follow.

"There! Stay where you are! Don't move!"

"I can't stay here," said another voice.

"Shall I shoot him now?" put in a heavy bass voice.

"No, wait a minute, I am coming over," said still another voice, and
then there was silence. The Rover boys looked at each other in
amazement. What did the talk mean?