In an unnamed Latin American dictatorship, a group of rebel freedom fighters fight to bring about a less oppressive society. The rebels, led by the enigmatic Enrique Carrasco (Lewis Collins) who has returned to his native land to fight, attack a hydro-electric dam. Along with Carrasco's native fighters are Smithy (John Steiner), a British people mercenary, and Maria, a native ex medical-student turned freedom fighter. After killing the security guards, Carrasco's men place explosives at a crucial point in the dam wall, when they blow the dam the resulting tidal surge destroys a nearby bridge that is carrying Government convoy.