A father and son on a summer rafting trip in Alaska hit a freak stretch of ice. Their raft flips over and both men are dragged under the ice by the fast running river. They survive the ordeal only to find themselves without shelter or food in freezing wet clothing in one of North America's remotest spots. The son leaves his dad to set out on an epic and perilous hike over mountains and rivers, along the way fending off grizzly bears. In a stroke of pure luck, after days alone, he is spotted by a lone passing plane and must reach his dad before it's too late.