Appleby's End (Inspector Appleby)

Appleby's End was the name of the station where Detective Inspector John Appleby got off the train from Scotland Yard. But that was not the only coincidence. Everything that happened from then on related back to stories by Ranulph Raven, Victorian novelistanimals were replaced by marble effigies, someone received a tombstone telling him when he would die, and a servant was found buried up to his neck in snow, dead. Why did Ranulph Raven's mysterious descendants make such a point of inviting Appleby to spend the night at their house?