The Squad investigate the murders of two males who had the word "Sorry" carved into their backs. The latest victim has a brother linked to Organised Crime, so three other officers are brought in, which Boyd takes an instant dislike to - except Greta. The new faces create tension in the office and the team cannot trust them. As the case goes on, they begin to realise that it could be leading to a paedophile group. (thetvdb.com)