
Seeking shelter from a rainstorm that has caused landslides and washed out all the roads in a remote area of Wales, several lost travelers find shelter in a gloomy mansion. It belongs to the strange Femme family - atheist Horace and his sister Rebecca, a religious fanatic and vicious fury.
Travelers Roger Penderel, Philip and Margaret Waverton are so tired and drenched that they suppress their fear when they meet the door-opener, a scary-looking servant or butler, a mute and lame Morgan. They are soon joined by the rather frisky and eccentric Sir William Porterhouse and his fiery friend Gladys DuCane, who also hasten to take shelter from the rain in the house. None of them would have stayed in this old house for anything if not for dire need.