When Gabriel Lawson dies of a heart attack and the police decide it was natural causes, his daughter hires Kerr and Rachael to investigate her suspicions that her stepmother is responsible.
A visit from a man who has received an anonymous email about their supposed investigation into the disappearance of his wife two years ago complicates things. Is it meant to distract them from looking into the death of Gabriel Lawson or is someone trying to help them by connecting the events?
Breaking their own rules, they take on both cases in the belief that there is a connection but it means they have to split up to cover more ground and that brings danger to them both as a resourceful adversary starts to target them before they can uncover the truth.