With DS Annie Cabbot about to take maternity leave, no-nonsense DI Helen Morton joins the team. A disturbing late-night message from his estranged brother Roy leads DCI Banks to go in search of him, without telling anyone. Meanwhile, DI Morton quickly alienates her colleagues with her tactless style at a murder scene, then makes matters worse by finding evidence linking Banks to the dead woman and speculating he could be a suspect. Banks delves deeper into Roy's life and uncovers questionable business transactions and associates. When Alan breaks the news to his parents that Roy has been murdered, they plead with him to find Roy's killer. Defying Morton, Banks returns to Eastvale CID and attempts to lead both investigations. He and DI Morton become convinced the key to cracking both cases lies with a woman being treated at a family planning clinic.