When Lana goes missing for four desperate days and returns refusing to speak of what happened, Jen fears the very worst. She thinks she's failed as a mother, that her daughter is beyond reach and that she must do something - anything - to bring her back. The family returns to London where everyone but Jen seems happy to carry on as normal. Jen's husband Hugh thinks she's going crazy - and their eldest daughter Meg is tired of Lana getting all the attention. But Jen knows Lana has changed, and can't understand why. Does the answer lie in those four missing days? And how can Jen find out?