Meek publishing assistant Ernest Broughton is surprised to receive a visit one evening from solicitor Everett Sloane, informing him of his rich Uncle Gabriel's death and that his presence is desired for the reading of the will. Unfortunately it is due to take place at Gabriel's imposing Yorkshire manor and, not fancying the journey alone, Ernie ropes in his best friend and flatmate, Syd Butler, to go with him.

After a strange encounter at the local railway station, Ernie's nerves are already on edge by the time they arrive at the house. He's soon reunited with his now decidedly dotty Aunt Emily, and meets snobbish cousins Guy and Janet; their father, Gabriel's brother, Michael; Dr. Edward Broughton; the definitely insane Malcolm; and the late Gabriel's nurse, Linda, and butler, Fisk.

The house has a decidedly spooky atmosphere but things get much creepier as night falls and the group separates and heads to their respective bedrooms. Creaks and bumps are surely just the weather playing with the building - but then the bodies begin to pile up... Who is responsible, and will any of them make it to morning alive?