Loosely based on Joseph Conrad's novel, "The Heart of Darkness", the film transplants the tale to the Vietnam War. A young American captain is given the assignment to hunt down and kill one of his own, a colonel, who has apparently gone insane. The deranged colonel murders hundreds of innocent people and constructs a strange kingdom for himself deep in the jungle, where he is deified by his followers.
Francis Ford Coppola has added 53 minutes of additional footage, including The French plantation sequence, an expanded Playboy playmates sequence, a new scene with Marlon Brando, and new footage of the navy patrol boat near the beginning of the journey up river.