Penny seizes the chance of a new life for her family when her husband is offered a job in Europe. At the airport, they meet charming Sophie, fluent in French and looking for work as an au pair. Soon, she becomes an important part of the family's life. But Sophie is definitely hiding something. Then Penny's toddler son is abducted. The police beg Penny and her husband to take part in a television appeal but unknown to the police, Penny and Seth are determined to protect their identities. Are their true identities linked to the abduction? And who has been watching them?