Four Atlanta businessmen, Lewis Medlock, Ed Gentry, Bobby Trippe and Drew Ballinger, decide to canoe down a river in the remote northern Georgia wilderness, expecting to have fun and witness the area’s unspoiled nature before the fictional Cahulawassee River valley is flooded by construction of a dam. Lewis, an experienced outdoorsman, is the leader. Ed is a good friend of Lewis and also a veteran of several trips but lacks Lewis’ machismo. Bobby and Drew are novices. While traveling to their launch site, the men (Bobby in particular) are condescending towards the locals, who are unimpressed by the “city boys”. At a local gas station Drew engages a young boy (implied to be inbred) in a musical duel, with the boy on banjo and Drew on his guitar. Although the duel appears mutual and Drew enjoys it, the boy does not acknowledge him when prompted for a congratulatory handshake.
The men spend the first day canoeing without incident, successfully negotiating the rapids that dot the river. About to go to sleep, Lewis takes off into the dark only to return a few moments later saying that he thought he had heard something or someone. In the morning while the others are still asleep Ed takes Lewis’s recurve bow to hunt but misses a clear shot he has of a deer.
Traveling in pairs, the foursome, in their two canoes, are briefly separated. Bobby and Ed, in the one craft, land briefly and encounter a pair of local hillbillies emerging from the woods, one of whom is carrying a shotgun. After a verbal altercation, Bobby is forced at gunpoint to strip, his ear twisted to bring him to his hands and knees, and then ordered to “squeal like a pig” before being raped by one of the locals. Ed is bound to a tree and held at gunpoint by the other man.
While the second local prepares to assault Ed sexually after the first has finished with Bobby, Lewis and Drew arrive, unnoticed by the locals. As soon as Lewis kills one of the rapists with an arrow from his bow, the other man dashes away into the woods.
A brief but hotheaded debate between Lewis and Drew concludes with Bobby and Ed’s voting for Lewis’s recommendation to bury the dead man’s body and continue on as if nothing had happened. Drew had wanted to inform the authorities, but Lewis has argued that the four of them would receive no fair trial for the killing, since the local jury would be composed of the dead man’s friends and relatives. His view is that the body will soon be buried by the water backed up by the dam and will never be found. Bobby, for his part, doesn’t want what happened to him to be known.
The four continue downriver but soon disaster strikes as the canoes reach a dangerous stretch of rapids. As Drew and Ed reach the rapids in the lead canoe, Drew shakes his head and falls into the water. It is unclear why.
When the survivors’ canoes collide on the rocks, spilling Lewis, Bobby and Ed into the river, Lewis breaks his femur and the others are washed ashore alongside him. Encouraged by the badly injured Lewis, who believes the escaped local is stalking them and shot Drew, Ed climbs a nearby rock face in order to dispatch the stalker with his bow. Bobby stays behind to look after Lewis. After reaching the top and hiding out until the next morning, Ed sees a man he takes to be the stalker appear on the cliff top with a rifle and look down into the gorge where Lewis and Bobby are located. Ed clumsily shoots and manages to kill the man, accidentally stabbing himself with one of his own spare arrows in the process.
Returning to the others with the body of the man he has killed, Bobby is uncertain that the dead man is the man who had fled from them earlier, but Ed convinces him that he is. Bobby and Ed weigh down the body in the river, to ensure it will never be found, and repeat the same with Drew’s body, which they encounter downriver. Lewis is too distracted with pain to do anything more than encourage this compounding of their hiding of what they’ve experienced.
Upon finally reaching the small town of Aintry, Bobby and Ed take Lewis to the hospital. To the authorities, the men present a cover story that Drew’s death and disappearance were accidental, with no mention of the four men’s encounter with the two locals. The story is clearly doubted by the local Sheriff Bullard and by Bullard’s deputy, whose brother-in-law, the sheriff says, hasn’t returned from a hunting trip back up there in the mountains. Having no legal basis to hold the men, Bullard simply tells them never to come back. Affecting levity, Bobby replies that they sure won’t.
With Lewis still hospitalized and in danger of losing his leg, Bobby and Ed take leave of each other to head home separately. Declining Bobby’s offer to handle it, Ed says he will carry out the duty of informing Drew’s wife of Drew’s death.
At his own home, Ed is comforted by his wife and returns to his role of husband and father. One night, Ed dreams of a dead man’s hand rising from a lake, which wakes him up and causes him to bolt upright in bed. His wife gently settles him back down beside her and tells him to go to sleep.