Jill is a psychologist, who's worried about her husband Ash. Their marriage is mostly comfortable rather than sparkling, but he's recently been concerned about their student daughter Rose and seems depressed. Ash is an osteopath who runs an alternative health centre on the Isle of Wight; Jill doesn't like him to go much beyond the bounds of conventional - or at least proven - treatments, and is particularly suspicious of Marguerite, a rather strange mute woman with extraordinary psychic and healing powers.