In the 1920s, Lady Constance de Momery presides over a costume ball for her grandson, but all is not as it seems and when young heir to the estate Felix de Momery announces his engagement to sweetheart Ruth, his friends Billy and Katherine seem far from pleased.

It's 1786, and Joseph Bloxham is a self-made man and something of a star in fashionable coffee-house society. Some, though, like the sceptical Noakes take a dim view of his shady business ethics. Bloxham has used his ill-gotten gains to buy the old Geap Manor, paying no heed to the warnings of Noakes and his friend Duncalfe, but when Bloxham starts to hear ghastly sounds in the newly-installed panelling of his drawing room it seems he might have more than just a mouse hiding in his wainscoting.

Back in the present day, commitment-shy Ben begins to discover that, though demolished, Geap Manor casts a long shadow. Having recently left his girlfriend Hannah for a life of excitement over cosy domesticity, he is excited by the curator's stories and screws the ancient door knocker to his new front door. However, he soon finds himself getting more excitement than he bargained for as the past begins to intrude rudely with a loud knock at the door in the night and a terrifying journey into Geap Manor's bloody past.