This is a short story in a larger series in which, in addition to the regulars we are so familiar with, Sherlock Holmes has a daughter, Lucy James. She's married to a young policeman, called Jack, who has a ten-year-old sister, Becky, for whom they are apparently responsible. (This is the first and so far only story in the series that I've read.) They also have a large dog, a mastiff called Prince.
This entire found-family group has received an invitation to Baskerville Hall for Christmas, ten years after the events of "The Hound of the Baskervilles." Sir Henry has been married to Beryl, the former Mrs. Stapleton, for eight yeas, and they have a five-year-old son, Hugo. Lady Baskerville is pregnant again, and due right around Christmas.
