Patrick Petfield DI Patrick Petfield (Ian Burfield) (2009-2010): Petfield is a serving police officer within the Metropolitan Police, holding the rank of Detective Inspector and working on active investigation teams. On two occasions, the UCOS team investigated cases previously worked by Petfield and interviewed him for information. The first was the death of Victoria Fleeting in a car crash after her bereaved husband David reported seeing her alive after her supposed death. The second was a fire at the Union Pub that killed four people and included a renowned gangster. In the Fleeting case, Petfield was hostile to the UCOS team for retreading on his old cases and in both cases the UCOS team made far better progress than Petfield in solving the cases. Whitehall Stephen Fisher Stephen Fisher (Tim McInnerny) (2011–2012): Fisher is a high-ranking Whitehall intelligence operative (and old acquaintance of DAC Strickland) who frequently uses UCOS operatives to serve his own ends, usually involving shady government deals. He first appears in "The Gentleman Vanishes", ostensibly as a supporter of UCOS advising Strickland to avoid a professional hitman. However, he does not always follow his orders, as he gives information that allows the team to attempt to arrest the hitman, although the operation does not go according to plan. In "A Death in the Family", Fisher blackmails the reluctant ex-cops into helping him with a case relating to government dealings with the Chinese by unearthing personal secrets and consolidates his minimal respect for the team with jibes about the detectives' weaknesses, particularly Brian Lane's alcoholism. However, he shows some regard for Jack Halford, calling him 'professional to the last'. When Jack passes sensitive documents regarding the case to a contact in the press, it was revealed that this was Fisher's intention all along—the information will now enter the public domain with only Halford at risk of being charged under The Official Secrets Act, and those involved will be too busy covering their tracks to pursue the culprit. In the final episode of the ninth series, "Part of a Whole", it transpires that Strickland first knew Fisher at Sandhurst and was part of a covert 'black bag' operation (a robbery) that went awry. This dark secret places all the former agents in mortal danger. Fisher nearly loses his life when shot by a gunman on a motorcycle and is last seen in the hospital, already plotting revenge against those