Quick recap
Lady Angkatell gathers family and friends for a weekend at her country house, The Hollow. Poirot, a neighbor, arrives for lunch and finds a scene that looks staged: Dr John Christow dying by the pool and his wife, Gerda, standing over him with a revolver. Before he dies, John says “Henrietta,” the name of the sculptor who was his lover. Gerda's gun isn't the murder weapon, and everyone seems set on confusing the police. Poirot sees the family is shielding someone. The killer really was Gerda, and Henrietta hid the evidence to honor John's last request. In the end Gerda dies by the poison she'd prepared for Henrietta.
No spoilersOpens once you mark the title as seen.