In the novel The Pale Horse, Martin Digby is the great-nephew of Lady Hesketh-Dubois.
It is suggested, although never confirmed, that Martin ordered the killing of his great aunt, using the "murder-for-a-price" service that formed the subject of investigation in the book. The procedure for ordering a killing is first to place a bet on the victim's life with commission agent Mr Bradley. The client would then be asked to pay a visit to the three witches at The Pale Horse in Much Deeping. Mark Easterbrook saw Martin's name in the guest book of the King's Arms Inn at Much Deeping, proving that for some reason, he had visited the village.