: Elsa Greer killed Amyas. She overheard him tell Caroline that the affair meant nothing and that he intended to send Elsa away as soon as the painting was finished. Spurned and vengeful, Elsa poisoned his beer.
Poirot concludes that while Elsa got what she wanted—Amyas's death—she ended up with a "living death," spending her life in bitter emptiness while Caroline died at peace. [S9E1] Five Little Pigs
Poirot investigates by interviewing the five other people present on the day of the murder: : Elsa Greer killed Amyas
: The "other woman" who sat for Amyas's final portrait. Poirot concludes that while Elsa got what she
: The devoted governess who witnessed Caroline's behavior at the scene.
Fourteen years before the main story, Amyas Crale was found dead at his estate, Alderbury, poisoned by . At the time, he was having a flaunted affair with his young model, Elsa Greer . Because Caroline had discovered the affair and allegedly stolen the poison from her neighbor's lab, she was convicted and hanged for the crime. Before her execution, she wrote a letter to Lucy claiming her innocence. The "Five Little Pigs" (The Suspects)