Based on the 1974 novel of the same name by Frederick Forsyth, it follows small mercenary unit of soldiers is privately hired to depose the president of a fictional African country modeled on Guinea-Bissau, Guinea-Conakry, Equatorial Guinea and Angola (as they were in the late 1970s), so that a British tycoon can gain access to a platinum deposit.

Having escaped from Central America with his comrades Drew, Derek, Michel, Terry and Richard, mercenary Jamie Shannon gets an offer from Endean, a British businessman working for a tycoon.

Endean's company is interested in "certain resources" in the small African nation of Zangaro, which is run by the brutal dictator, President Kimba.

Shannon's activities arouse the suspicions of the police (especially a suspected dalliance with a woman who turns out to be one of Kimba's mistresses) and he is arrested, severely beaten and imprisoned.

Provided with a million dollars for expenses, Shannon contacts some of his associates from Central America and they meet in London to plan the invasion.

The group illegally procures a supply of Uzi submachine guns, ammunition, rocket launchers, mines and other weapons from arms dealers.

Drew bursts into a shack in the barracks' courtyard and finds only a young woman with a baby; when he turns to leave without harming them, she shoots him in the back with a pistol.

Shannon introduces Dr. Okoye as Zangaro's new president who tells Colonel Bobi that he is under arrest, and when Endean protests ("This whole country's bought and paid for!

Shannon, Derek and Michel load Drew's body onto a Land Rover, in line with the toast they drank on planning the operation "Everyone comes home".

Jewison hired Michael Cimino to direct with Clint Eastwood and Nick Nolte starring, but he dropped out of the film in order to work on Heaven's Gate and John Irvin became director.