A small inexperienced team of four British operatives are hired by British Intelligence to infiltrate into Iran and carry out a reconnaissance mission on a small isolated farm on behalf of the CIA. The CIA believes that American hostages have been separated from the main group at the American embassy in Tehran, and are being held at the remote farm. The mission turns into a fool's errand, and the team then go on a tortuous and tragic mission, filled with twists and turns every step of the way involving the CIA, Russians and Mujahedeen. They then tenuously call in the biggest favour of all time to help them escape from Iran, to get home and get even with the CIA.