 Pete is guiding lodge guest Mr Johnson along the Aux Sables river. When Nancy learns that Mrs Johnson has gone into labour, Dennis flies with Billy to take Mr Johnson home, leaving Billy with Pete to return with the canoe and gear. Pete tells Billy about strange "clues" discovered by he and Mr Johnson - an inukshuk with a directional arrow and a boy s school jacket. Billy and Pete decide to canoe down the river and investigate further. Dennis meanwhile hears a radio bulletin that 14-year-old Norman Cartwright has been kidnapped and takes Officer Nixon with him to find Billy, Pete and the kidnap victim.