A seemingly straightforward arms deal goes awry for Liam who, whilst deep undercover, attempts to entrap gangster Charlie Peace after the murder of a police chief in which he is the principal suspect.

Liam and Garth are brought in to negotiate with kidnappers when the grandchildren of media mogul Clayton Waddington are taken hostage. Meanwhile, Kelly pretends to be homeless in an effort to infiltrate the anti-capitalist group that is claiming responsibility. However, time is running out for the hostages.

Garth and Liam masquerade as insurance company ransom negotiators after the grandchildren of a wealthy media magnate are kidnapped. Garth makes the acquaintance of Waddington's grandaughter, but his expectations are confounded.

Garth and Kelly sign on to an Internet dating site to catch a serial killer.

Garth and Kelly sign on to an Internet dating site to catch a serial killer.

Liam and Garth go undercover to gain the trust of an arrogant armed robber.

The undercover operation against Sean Denning escalates as a court hearing approaches.

A bunch of soldiers previously undercover in Northern Ireland feel that the Ministry of Defence have treated them unfairly, in response they threaten to begin their own campaign of bombing.

Garth and Liam remain deep undercover in their attempt to foil a group of ex-soldiers intent upon committing terrorist acts within the UK, with the Houses of Parliament as the primary target. The two are forced to escort the bomb so as not to blow their cover.

A drug lord behind bars in a high security prison orchestrates criminal operations from within, but after the murder of a key witness in his case Garth goes undercover as a prison warder to obtain information.

Liam and Garth remain deep undercover in their attempt to foil a underworld figure responsible for a significant amount of drug traffic. It becomes apparent that one of the prison guards is in the employ of Hunter.