Liam infiltrates a white supremacist group which has begun a systematic petrol tanker bombing campaign. Garth is assigned to provide backup and support to Liam's family, but when a vengeful man - whose imprisonment Garth was responsible for - tracks him down, he finds instead that his presence is putting them in mortal danger.

Liam discovers that the leader of the white supremacist group is not who he seems. An unwelcome visitor from Garth's past mistakes Liam's family for Garth's - and sets out to exact his revenge on the man whose evidence put him in prison.

Liam and Garth pose as drug dealers in a bid to capture Jamie Lamb, the country's biggest cocaine importer. They infiltrate his trusted entourage and fit in so well that when Lambs wife leaves him taking his two daughters with her, he asks Liam and Garth to kill her and bring back proof in exchange for a shipment of cocaine.

The second part of the story in which Liam and Garth infiltrate drug baron Jamie Lamb's gang. Kelly persuades Tania Lamb to help them fake her murder. Only when the ""proof"" is taken back to Jamie, he turns nasty and ups the stakes, declaring that the deal is not complete until his daughters have been returned to him. Liam and Garth have are forced to use Lamb's daughters as insurance to make sure the exchange of drugs takes place. In a fit of guilt, Tania calls Jamie and unwittingly exposes Garth and Liam's set-up leaving them cornered with no back up.

Police Chief DI Holland challenges gangster Charlie Pearce in order to regain control of a tough area of the city, but is shot dead on his way back from a public meeting with the area's residents. Pearce is, of course, the chief suspect. Liam, Garth and Kelly set themselves up as an operation selling expensive fake watches and it's not long before Pearce and his heavies call round for their first 'insurance' payment. Liam is embraced into Charlie Pearce's fold when, through a stroke of good fortune, he saves Pearce's life. Unfortunately Garth's unresolved issues with his brother Chris land him in deep trouble when Chris tracks him down and blows his cover. Liam's nerve is tested to the limit as he faces the choice of killing his partner Garth to prove his allegiance to Pearce, or coming clean and risking being killed himself.

Gangster Charlie Pearce invites Liam to get involved with a lucrative gun shipment for Jeff Mohandas. The deal becomes further complicated by Pearce's daughter-in-law, Kim, who is having an affair with Mohandas and has hatched a plot to kill both her husband David and Charlie Pearce. Liam, once again, finds himself out of his depth and without backup as a series of double-crosses turn a simple deal into a bloodbath.

A group of soldiers, trained to go undercover in Northern Ireland, feel they have been treated unfairly by the MOD and threaten to start their own bombing campaign.

Liam and Garth continue their infiltration of a group of former soldiers threatening to terrorise the UK. The Houses of Parliament are the target and Liam and Garth must travel with the bomb rather than reveal their identities.

A drugs baron on remand in a Category A prison is still conducting his business with the outside world. When one of the witnesses in his case is found murdered, leaving only one remaining and in terrible danger, Garth goes undercover as a prison warder to observe him.

Liam and Garth's undercover mission continues, as it becomes apparent that one of the prison guards is working for drugs baron, Hunter.