Lady Edgware, a famous actress who left her husband years ago, asks Hercule Poirot for assistance. She wants a divorce so badly that she utters that she will even murder him. And then the murder happens, and witnesses say they saw lady Edgware at the scene, but she has an alibi.
The ABC Murders (1936)
Hercule Poirot receives a letter warning him of a murder in a town called Andover. After the murder happens, he receives another one, warning of another murder in the town of Bexhill-on-Sea. Will Hercule Poirot catch the murderer before it's too late?
Dumb Witness (1937)
Poirot receives a letter from an old lady who believes she has had a narrow escape from death. When Poirot and Captain Hastings go to investigate, they learn that the lady passed away months ago. The lady has also changed her will just before dying, and everything went to her companion and not her relatives.
Curtain: Poirot's Last Case (1975)
Captain Hastings and Hercule Poirot, now a cripple and on his deathbed, have returned to Styles to solve a final mystery together.
These four stories can be found in the Complete Battles of Hastings volume 2 omnibus.
Having read the last of the Poirot stories, I feel kind of sad. Hercule Poirot (and Captain Hastings) has been a great companion for a long time. I am still shocked over how things ended in Curtain, but at the same time that's the first time Agatha has disappointed me.
I have been trying to compose a list over my favourite Poirot stories, but that has proven to be impossible; I seem to get a new favourite every time.