On a perfect summer's day, at a school picnic beside a lake, a little girl goes missing, leaving a family devastated and a community asking questions. Seventeen years later her sister, Stephanie, is practising as a psychiatrist. A new patient's revelations force her to re-examine her sister's disappearance. Why are their stories so similar? Unable to let the matter rest, Stephanie embarks on a journey to find out what happened to her sister.