When the battered body of a French student is found on Twickenham Green in London, hardworking and humble DCI Colin Sutton is appointed the lead detective on his first big case. Despite objections from his superiors, Sutton believes the young woman's murder may be connected to a previous attack and embarks on a quest to catch a serial killer. Realistically portraying the ins and outs of police investigations, it tells the story of one detective's uncompromising search for justice.