Quick recap
Cruel old millionaire Simeon Lee summons all his children to Gorston Hall for Christmas, including his black-sheep son and Pilar, a Spanish granddaughter no one has met. He toys with them, threatening to change his will. On Christmas Eve the house hears a crash and a scream. They break down his locked door and find Simeon with his throat cut, blood everywhere, and his diamonds gone. Poirot, spending the holiday nearby, helps Colonel Johnson and Superintendent Sugden. In the end the killer is Sugden himself, Simeon's illegitimate son. The scream was staged after the murder, with the door locked from outside.
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