In a run-down South American town, four men are paid to drive trucks loaded with nitroglycerin into the jungle through to the oil field. Friendships are tested and rivalries develop as they embark upon the perilous journey.

The cruel and abusive headmaster of a boarding school, Michel Delassalle, is murdered by an unlikely duo -- his meek wife and the mistress he brazenly flaunts. The women become increasingly unhinged by a series of odd occurrences after Delassalle's corpse mysteriously disappears.