No job? No family? Few friends? MI5 wants you. After acting on poor intelligence, officer Paul Tallis shoots a suspected terrorist in a Birmingham shopping centre. With his career over, Tallis leaves the elite firearms unit and is utterly disillusioned.A year later, Tallis is approached by a shadowy figure working for MI5. The offer is simple - unearth four dangerous illegal immigrants accidentally released from prison and hand them over to the authorities.At first, the plan runs like clockwork, but then Tallis makes an ugly discovery. Suspecting he's being set up, Tallis smells a conspiracy, but now the authorities are demanding the last exile - only this time the man is innocent.