With his career and access to the Stevie case resting on the outcome of his psychiatric report, River must keep his unofficial investigations into Stevie's passing to himself. This sends tensions high with his new partner Ira, who fears being dragged down by River's instability, and Chrissie, who needs River working on his own caseload, most pressingly investigating a suspicious workplace accident that has left a foreman fighting for his life.
But River's mind is elsewhere as the discovery that Stevie has been keeping secrets forces him to reassess how well he knew his best friend and colleague. Unearthing new information about who Stevie spoke with in the lead-up to her cuddle throws suspicion on somebody close to her - somebody with real motive.
Respected police officer John River, a gifted cop with a troubled mind, struggles to come to terms with the recent loss of a close colleague, and chases a potential suspect across London - with tragic consequences. Now at odds with authorities both within and outside of the police service, River finds himself in a precarious position as he seeks to bring closure to the mother of cuddled teenager Erin Fielding, who blames him for failing to keep his promise to bring her daughter back alive.