DS Tommy Murphy is called back to work after a leave of absence to be at his mother's side. His new job is to attempt to get close to Drew and Billy Johnstone, vicious Belfast criminals now operating in Leicester. Murphy thinks he's found himself a way in when a drug deal goes awry.

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.