A parent's worst nightmare comes true in a gripping five-part psychological thriller from the producer of Missing You and Fool Me Once. Mother-of-two Elisa Blix (Denise Gough) is delighted when her nine-year-old daughter Lucia (Beatrice Cohen) makes a new best friend at school, Josephine (Robyn Betteridge). Josephine's mother Rebecca (Holliday Grainger) is incredibly friendly so Elisa doesn't think twice when Lucia asks if she can go to a sleepover at Josephine's house. The following morning when Elisa goes to collect Lucia, she discovers the girls and Rebecca have vanished without trace and Rebecca's home is in fact a rental property. Elisa and her husband Fred (Jim Sturgess) are caught in the eye of a media storm as police launch a manhunt and their abilities as loving, protective parents are called into question