Poor Poirot. There's no heat in his apartment, and it's not being fixed until after Christmas. Then this old man, Simon Lee, calls him and says he needs Poirot at his country home over Christmas, though he's not given an explanation as to why. Poirot has one question: Do you have heat? He's on his way.
Simon Lee is a perfectly awful man. In the beginning of the episode, we see an incident which took place 40 years earlier in South Africa, when Lee and his partner find diamonds. Lee kills his partner but is injured and is taken in by a woman who is disfigured by a port wine stain on her face. It's obvious she falls for him, but one night she discovers that he's disappeared.
Lee hasn't changed much. He has summoned his family to his home and he wants Poirot to watch them. "For what?" asks Poirot. "You'll know when you see it," Lee answers. What Poirot sees later is Lee's murdered body which was in a locked room.
The whole family makes up the list of suspects. Two sons, one of whom hasn't been around for years, a granddaughter, Pilar, the child of Lee's late daughter, and two daughters-in-law.
Soon, a local detective and Inspector Japp turn up.
I understand this is not a faithful adaptation of the book, and one reviewer here said he was glad Agatha Christie wasn't alive to see her work changed. Once the estate gets its money, it's obvious that they don't care what anyone does to the stories. If Christie were alive, I imagine things would be different.
I enjoyed this one, but that's because I don't remember the book.