Lara and her one-year-old son, Arthur, are brought to experienced foster carer, Cathy Glass, by their social worker. Lara has fled an abusive relationship and Arthur has suspected non-accidental injuries. Cathy must monitor Lara whenever she is with her son, day and night. She cannot let them out of her sight for a minute.

Lara loves her son, but she puts her own needs first. Cathy must teach Lara how to care for Arthur, but will it be enough to allow her to keep him?