In the 1920s Harry Price, a medium and exposer of fake clairvoyants, is approached on behalf of rising MP Edward Goodwin, whose young wife Grace's odd behaviour causes her to believe that their house is haunted and she is being made to obey the commands of ghosts. Goodwin is sceptical, feeling that Grace's problem is psychological, but he will not have her committed - partly so as not to harm his political career - and asks Harry to move in following mysterious, sinister writing on a floor. Helped by sensible housemaid Sarah and opportunistic journalist Vernon Harry researches the house's history, learning it was previously a workhouse where a young boy, Grace's possible ghost, was murdered. However he also discovers personal secrets from the Goodwins' past, which make Grace susceptible to her alleged visions.