In one of those fictitious South American countries, a moderate new leader is about to be inaugurated, much to the dismay of the generals. When an assassination attempt fails, they send an agent to the US to contact Martin Fierro (Estrada), a former Green Beret. His father, a leftist
newspaper editor, was murdered by the old regime, of which the new president was a member. The agent of the generals tells Fierro that the president was the man responsible. Estrada flies down and prepares to assassinate the president, but the local CIA man, Merrick (Vaughn), gets wind of the
attempt and trys to foil it. Numerous car chases, train-top fistfights, and gun battles ensue....