After living in France with his wife Susan for the last 15 years, Christopher Edwards places a desperate call to his stepmother back in England for financial help. But when Tabitha relays the details of their conversation to the police, a resulting double homicide investigation quickly builds steam, and the couple’s carefully reconstructed lives are suddenly placed at risk.

Shortly after turning themselves over to the Nottinghamshire Police, Susan and Christopher are thrown into separate holding cells, where their statements are picked apart by detectives Emma Lancing and Paul Wilkie. As the past comes back to haunt her, concerning details from Chris’ interview make their way to Susan, and a painful secret is revealed.

As they narrow in on the likeliest scenarios from that tragic night, Lancing and Wilkie’s focus shifts to Christopher’s past. While they exploit his recurring tendency to go too far for those he loves, the couple’s relationship with Susan’s parents comes under the spotlight. Then, Lancing and Wilkie have a breakthrough that calls the couple’s shared reality into question.