How do you solve an unsolvable murder? Ask the victim... In January 1986, newly engaged Marnie Driscoll is found dead in her parents' kitchen. With no witnesses, it seems as though the circumstances of her death will remain a mystery.

Six months later, high-flying Detective Inspector Andrew Joyce's career takes an unexpected detour when he finds himself unwillingly transferred to an obscure department within Greater Manchester Police, known as the Ballroom. The Ballroom team employs unorthodox methods to crack previously unsolved cases, and Joyce, a sceptic by nature, must find a way to work with Peggy Swan, a reclusive ex-socialite with a unique talent: she can communicate with the dead. Joyce soon discovers that Marnie's death, initially dismissed as an opportunistic act of violence, actually seems to be a carefully orchestrated murder.

It will take both Joyce's skill as an investigator and Peggy's connection to her new ghostly charge to navigate the web of secrets surrounding the case and bring closure to Marnie's tragic story before the killer can strike again.