The Mysterious Affair at Styles (Agatha Christie's Poirot)
https://www.youtube.com/watch?v=2k1UlzL4oiU
"The Mysterious Affair at Styles" was adapted for the ITV television series, Agatha Christie's Poirot, starring David Suchet as the eponymous detective. Here is the feature-length episode from season two adapting Christie's debut novel.
Hercule Poirot Is Dead; Famed Belgian Detective
Hercule Poirot is the only fictional character eulogized by the New York Times after the publication of Christie's final two novels, which she planned to be published posthumously. Here is his famed obituary.
Soft-Boiled
https://www.newyorker.com/magazine/2009/08/03/soft-boiled
Louis Menand, literary critic, writes about Thomas Pynchon's detective novel, Inherent Vice, and draws comparisons to hard-boiled traditions like Raymond Chandler's Phillip Marlowe and more "theatrical," eccentric characters like Christie's Poirot.
The Project Gutenberg e-book of The Mysterious Affair at Styles, by Agatha Christie
https://www.gutenberg.org/files/863/863-h/863-h.htm
A link to the free, full-text version of Christie's debut novel, The Mysterious Affair at Styles, courtesy of Project Gutenberg.