A detective returns to work after sustaining a near-fatal bullet wound, and begins an investigation to uncover the identity of the person responsible for killing a notorious drug baron.
London Metropolitan police detective Colin Sutton tracks down a serial killer. The series is a dramatization of the real-life murder of a French woman in London in 2004, and is based on the police detective's notes, which adds an air of realism to the procedural elements of the series.
DC Anna Travis joins a team on the hunt for a particularly gruesome serial killer. When the latest victim is found and doesn't fit the usual profile of the killer's victims, Travis sets out to prove herself.