Nadir and Hunter investigate an apparent protection racket following a tip-off from Nadir's informant. However, Hunter is suspicious that not all could be as it seems when one of the victims hands over more than £2,000 in cash. Their subsequent investigation uncovers a plot to have a couple murdered, forcing Perkins to go undercover as the contract killer. Meanwhile, a crash between an ambulance and a car soon turns awry when a convicted murderer, who has been sentenced to life in prison, escapes from the back of the ambulance. Gold soon discovers that the occupant of the car has visited the prisoner several times whilst he has been in jail, and that the crash is no coincidence.
