Detective Inspector David Bradford has always been a maverick, but his behavior is spinning out of control. When Detective Sergeant Vivienne Cole pulls him up on his conduct, he announces that their professional relationship is over - and then he goes AWOL. When Vivienne tracks David down and demands he explain his behavior, what he reveals knocks her sideways.

In season 3, the elite murder investigation team deals with a series of killings - which turn out to be linked. It soon becomes clear that the killer has access to information from within the police service itself - are the detectives hunting one of their own?

The elite murder squad returns. As the detectives solve each case - skeletal remains dug up in the garden, the brutal murder of a pub landlord, a teenage au pair found dead in a very compromising position, the double-shooting of a father and son - there's one mystery Detective Inspector David Bradford can't unravel - where is his wife Sarah? As the other detectives investigate why David is lying to them about the night Sarah disappeared, they begin to think the unthinkable - did the Detective Inspector murder his wife?