Maxwell is living a nightmare when he begins to question whether his fiance Imogen is his own sister - separated by adoption. Worse, he fears that she may already know that she is, and is marrying him anyway. A visit to her birthplace in Cambridge stirs up some deja vu that confirm Maxwell's troubles. Former DCI Morris Keene languishes at home, struggling with a debilitating injury. DI Chloe Frohmann's new partner is all too willing to believe the worst when Morris' daughter Dora is accused of assisting a suicide. Buried skeletons discovered next to an old barn link the suicide and Imogen's childhood, revealing horrors in the past and triggering danger in the present.