Valentine and Kapoor investigate when a car belonging to a factory owner is set on fire, and discover that the culprit was one of his former employees, who reveals that he has been employing illegal immigrants as cheap labour. Valentine informs one of his old pals at Barton Street, Sgt. Harry Haines, and the pair conduct a raid, only to leave empty handed. Valentine suspects something fishy is going on – and his suspicions are confirmed when Haynes offers him a bribe to keep quiet. Meanwhile, Harman and Johannsen are tasked with accompanying a vulnerable witness to court, but in the process stumble upon a protection racket, and Murphy accepts a transfer to the Child Protection Team.