Things haven't been going well for Beth. Her husband has left her for one of her friends. Her fellow school mums judge her for swearing too much and not shifting the baby weight. And now she's stuck in A&E after her son fell off the climbing wall on the first day of school. In fact, things haven't been going well for Beth since Charlotte died - her best friend, a favourite at the school pick-ups and the only person to ever run an interesting PTA meeting. But after being hit by a car while on an ill-timed evening jog, Charlotte is no longer there to help Beth pick up the pieces of her increasingly difficult life. That is, until Beth discovers that Charlotte left her toddler alone in the house during that fatal run. The Charlotte she knew would never do something so irresponsible, and suddenly Beth is questioning whether Charlotte's death was really an accident.