Now that Baker knows Murphy is a cop, he must race against the clock to find Kim before her secret is revealed too. However, local Chief Superintendent Bowry cares less about Kim's life and more about his own reputation and funding, and Murphy is forced to take desperate measures in his hunt for his missing friend.

With Mitch dead and Kim still missing, it's time for a heavily guilty Murphy to go undercover in the hope of finding Kim before it's too late. What awaits him is a world of people trafficking, drug smuggling and unwilling prostitution.

Murphy is working as a cover officer for an old friend, Mitch, and his fellow undercover officer, Kim. However, there are tensions between the two undercover officers and when they go missing Murphy is determined to find them.

Murphy ends up being exposed and caught up in a vicious and final showdown between brothers Drew and Billy Johnstone.

Working deep under cover, Murphy manages to gain the trust of Billy Johnstone, while trying to uncover the associations between his brother Drew and a local Asian criminal network.

The operation against Callard builds to its conclusion as Murphy is hired to help complete a shipment of Afghan heroin into England. His undercover work could help secure the conviction, but Murphy's presence is demanded elsewhere, as a key prosecution witness in the High Court.

Callard starts systematically destroying the forensic evidence. Murphy and Miller fear that he may want to destroy one or both of them too.

Following a bungled attempt to close down an elaborate Russian crime-ring, Murphy and Guthrie find themselves embroiled in what appears to be a textbook crime of passion. An unknown blonde is busy murdering London's successful businesspeople. The only link is that all the victims are members of a state-of-the-art health club in the heart of the City.

When Guthrie is fatally stabbed in an alleyway, Murphy cancels his holiday to investigate. She was working undercover in the case of three murders of homeless women. Murphy in turn poses as a homeless man to find what the press is calling the return of Jack the Ripper. He takes up residence in a homeless shelter and befriends a teenaged refugee who may have witnessed one of the killings. He also has his eye on resident counsellor and religious advisor, Reverend William Norris.

Murphy finds himself going undercover with INTERPOL to smash a car smuggling ring run by Godfrey Raines with his son and daughter. Murphy manages to convince Raines that he too is a car thief specialising in high-end vehicles. He soon realizes that INTERPOL is after something else when they delay arresting Raines and start questioning about arms shipments. Into the picture comes former MI6–turned–criminal Mr Davidson.

In the glittering world of the West End club scene, the head of security of a well-known East End gang is found murdered. Prime suspect: gang leader Carl Tate. In order to prevent another 'door wars', Murphy joins Tate's gang undercover, but when warfare escalates, Guthrie is compelled to join ranks on the doors of Tate's latest venture, X-Club.

Murphy goes undercover in a convent when a young nun apparently commits suicide and a second vanishes. Posing as a priest, he finds any number of suspects. The older nuns obviously have a secret and are in league with a pharmaceutical firm. Murphy suspects they may be participating in illegal or unauthorised drug trials in their African mission.

A team of undertakers moonlight as diamond thieves, and the bodies are stacking up. Detective Sergeant Tommy Murphy goes undercover and discovers a nefarious connection with Japanese heroin dealers. Meanwhile, team leader Hatcher plans the most audacious heist yet. Murphy has to hold his nerve in an epic final showdown.

Callard recommends Murphy to the McGeechan brothers. They plan to reactivate some assault rifles, but won't tell Murphy why they need them. Murphy knows they plan something big, but first he has to make sure his cover isn't blown.