His thick and fast-growing medical file says he should be retired but Detective Martin Murphy wants to get back on the streets, doing what he does best. Murphy has been given one last chance. After a terrible experience working undercover in Northern Ireland, he's in London and about to fail another psychological assessment. While his life spirals out of control, his boss sends him back undercover to expose a gang of diamond thieves who have just burnt a security guard alive. As he gets closer to the gang leader, Murphy realises their plans are more ambitious and more deadly than anyone expected...