An American writer goes to a remote Welsh manor on a $20,000 bet that he can write a classic novel like 'Wuthering Heights' in 24 hours. However, upon his arrival he discovers that the apparently empty manor has several rather odd inhabitants.
Relatives gather at a haunted mansion for a will reading where the sole heir is threatened by a clause that could disinherit her if she goes mad, all while a homicidal maniac escapes nearby.
A woman recovering from a nervous breakdown tries to convince her husband and and the local London police that she has witnessed a murder in the abandoned house next door.