One dark December night, in a small seaside town, a little girl is found abandoned. When her mother arrives twenty frantic minutes later, authorities release the pair, believing it to be an innocent accident of a toddler running off.

But when a man is found beaten and left for dead in his apartment and a bedroom is discovered to contain a padlock and–most worryingly of all–children’s toys, DS Joanna Harper begins to suspect the little girl on the seafront was not who her mother claimed. Worse, when CCTV footage reveals an image of the pair, Harper realizes she knows the woman almost as well as she knows herself: it’s her estranged daughter, Ruby.

Desperate to reach Ruby before the police find her, Harper knows her deception might just cost her everything. But if it means choosing between her daughter or her career, Harper knows there’s no question. She’ll protect her daughter no matter what. But what Harper doesn’t know is that someone–or something–else is searching for Ruby and the little girl, too. Waiting to bring them home . . . once and for all.