After escaping from the assassins of a gang boss, Jackie Scanlon (Roy Scheider) settled in a South American village far from civilization. One day he and three other workers from the village are given the task of preparing two old trucks and using them to transport a load of highly explosive dynamite to a burning oil well. Since the fire cannot be extinguished with water, the flames are to be extinguished with a huge explosion. However, due to incorrect storage, the explosive is unstable; the nitroglycerin in the explosive rods has expired and threatens to explode at the slightest vibration. Constantly threatened by their deadly cargo and the perils of the jungle, the four adventurers' sweaty journey through hell begins...