After a brief stint in the London Mayor's Office, Detective Constable Cat Kinsella and her partner Luigi Parnell are put on the case of a young Australian woman who turns up dead after a party. In this follow-up to Sweet Little Lies, the suspect is Joseph Madden, the owner of a coffee shop around the corner. Madden insists he's innocent, that he was home with his wife Rachel at the time of the murder, but she contradicts his alibi, swearing that she was home alone. One of them is lying, and Cat is tasked with getting to the heart of the Maddens' marriage. As she tries to balance the demands of the investigation with a budding romance and unresolved family drama, Cat has to decide how far she'll go to keep her own past mistakes buried.