John Mercer's predecessor, Patrick Finch, has gone on a vigilante-style rampage, meting out his particular brand of justice against drug-dealers and prostitutes. He is working on his own and he's making newspaper headlines. It's time to put the brakes on Finch.
Meanwhile, Hugh Berry, the man who sorts out the paperwork to cover Lenny's illicit activities, asks him to take out a hit on his behalf.
A hit-and-run driver Trevor Bowyer rendered Hugh's grandson mentally disabled. But the driver only served two years for the crime. Lenny is left in no doubt that if he doesn't send his hit man tohug Bowyer, Hugh will find one of his own.
Lenny visits Finch in an attempt to bring him into line. But he finds a bitter, alienated and menacing man. Finch is everything Lenny feared he might become.
Leaving Finch's tower block, Lenny is furious to find Hugh Berry waiting outside, he's clearly tempted to hire Finch in order to take out Bowyer.
As crime ravages Britain with daily news of shootings, gangs out of control and rumours of corruption within the establishment and the police seemingly losing the battle, who can bring order?
John Mercer is a former member of the Special Forces serving a double life sentence. He is released from prison unexpectedly early and introduced to the shadowy Lenny Douglas, a police officer retired on grounds of ill health. Mercer realises his newfound freedom comes at a price. Douglas pulls together an unofficial operation with a single brief - to remove untouchable criminals from society. Mercer must use the skills he learned in the Special Forces to execute a series of discreet hits.
To help him complete each mission, Mercer is introduced to his new colleagues who include Calum McKenzie, a petty thief whose main interests are girls, drugs and music. Things are complicated by the final member of Douglas's group - the sharp tongued but seductive Rose, an ex-copper forced out of the police by scandal, she has always used her sexuality as her primary weapon and is more than a match for Mercer. The gang operates outside the parameters of the law and is at odds with the world but when it comes to fulfilling its mission it is lethally effective.