Murphy is out posing as a criminal armourer to make an arrest. During the set-up he recognises Caz Miller, a man known for his connections to criminal gang leader and known cop-killer Dave Callard. Miller tells Murphy that he wants to kill another gang member called Richard Holloway. Murphy stops the planned arrest because he thinks he can gain Callard's trust and infiltrate the entire criminal organisation to take everyone out. (thetvdb.com)