Persons unknown / Susie Steiner.

As dusk falls, a young man staggers through a park, far from home, bleeding from a stab wound. He dies where he falls, cradled by a stranger, a woman's name on his lips in his last seconds of life. DI Manon Bradshaw can't help but take an interest - these days she only handles cold cases, but the man died just yards from the police station where she works. She's horrified to discover that both the victim and prime suspect are more closely linked to her than she could have imagined. And as the Cambridgeshire police close ranks against her, she is forced to contemplate the unthinkable. How well does she know her loved ones, and are they capable of murder?