The head of a British Secret Service division, Mostyn (Trevor Howard), decides to hire his old army pal Boysie Oakes (Rod Taylor) to liquidate rogue spies who are causing problems for the agency. The only problem is that Oakes has a phobia about flying and no appetite for violence, and is in every way the wrong man for the job. The solution Oakes comes up with is to subcontract the work to an underling, which works fine -- until he has to get his own hands dirty.