They know she killed them. They've just never known why. Connie Cross was a trusted pharmacy assistant when she was arrested for the gruesome murders of at least seven strangers. Now, she's serving a whole-life order for the shocking crimes she refuses to explain. Olivia Lang never forgot Connie, the awkward teenager from a south London estate she first met while working for the police. Twenty years later, Olivia is desperate to understand what made Connie turn into a murderer. But as she begins to uncover the truth about the UK's most notorious female serial killer, Olivia risks revealing secrets she's kept hidden for years.