A haunted child. A desperate mother. An unspeakable truth. 'She's my daughter, but in some weird way I feel she isn't really my child'. Young single mum Grace is drowning. Her little girl Sylvie is distant, troubled and prone to violent tantrums which the child psychiatrists blame on Grace. But Grace knows there's something more to what's happening to Sylvie. There has to be. Travelling from the London suburbs to the west coast of Ireland, Grace and Sylvie embark on a journey of shocking discovery, forcing Grace to question everything she believes in and changing both their lives forever.