One mistake could cost her everything. Susannah has two beautiful daughters, a high-flying medical career, a successful husband and an enviable life. Her hair is glossy, her clothes are expensive; she truly has it all. But when - on the hottest day of the year - her strict morning routine is disrupted, Susannah finds herself running on autopilot. It is hours before she realises she has made a devastating mistake. Her baby, Louise, is still in the backseat of the car and it is too late to save her.