In a country house party in Wiltshire in 1694, a member of the landed gentry, Mrs Herbert, signs a contract with the draughtsman, Mr Neville. They agree that he will produce twelve drawings of her husband's property, Compton Anstey, in return for bed, board and a sexual liaison with her, for each drawing produced. All parts of the agreement will be undertaken in her husband's absence.

To maintain a consistency within each drawing, the draughtsman returns to each location at the same time of day and also instructs all members of the house to recreate the same circumstances at these particular times. His attempts at command to this effect, and his social difference to others in the property (he is a Scottish Roman Catholic and also of different class), bring him into conflict with Louis Talmann, the Herbert's son-in-law and German Protestant who hopes to establish his offspring at Compton Anstey. He and his wife, Sarah Herbert, are as yet childless.

Following Sarah's revelation to the draughtsman that each of his drawings features an item of clothing belonging to the missing Mr Herbert, she proposes that they, like the draughtsman and her mother, enter into a sexual arrangement.

Mr Herbert's corpse is found in the property's moat. The estates manager, Noyes, who, it is revealed, was once engaged to the now Mrs Herbert, is concerned that he may be implicated in the death, and blackmails Mrs Herbert with regard to the incriminating contract. The draughtsman's drawings are sold to Talmann, the money from the sale going to Noyes. Talmann believes the drawings contain evidence of his wife's infidelity with the draughtsman, but his wife points out that they also offer evidence of Talmann's designs on the estate and his knowledge of Herbert's death.

Neville returns to the estate later in the autumn to produce a thirteenth drawing of the house, this time recording the location of Herbert's body. This is again accompanied by a sexual liaison with Mrs Herbert, who reveals that both she and her daughter used Mr Neville to obtain heirs. That evening Noyes, Talmann and Seymour (another member of the local gentry) blind and kill Mr Neville.