Croydon, 1964. Helen Hansford is in her thirties and an art therapist in a psychiatric hospital where she has been having a long love affair with Gil: a charismatic, married doctor. One spring afternoon they receive a call about a disturbance from a derelict house not far from Helen's home. A 37-year-old man called William Tapping, with a beard down to his waist, has been discovered along with his elderly aunt. It is clear he has been shut up in the house for decades, but when it emerges that William is a talented artist, Helen is determined to discover his story.