Edward Pengelley

In the short story The Cornish Mystery, Edward Pengelley was a dentist in the Cornish town of Porgarwith. His wife, Mrs Pengelley sought Poirot's help because she feared he might be poisoning her. She thought his motive was a "yellow-haired hussy", the dental assistant, Miss Marks, whom Edward employed in his clinic.

After Mrs Pengelley died, Edward Pengelley announced his engagement to Miss Marks. The "voice of the people" or "vox populi" soon resulted in a petition being sent to the Home Secretary. The body of Mrs Pengelley was exhumed and found to have large quantities of arsenic. Edward was arrested and tried for murder. His case appeared bleak until Poirot stepped in to rescue him.

Portrayals
Edward Pengelley was played by Jerome Willis in the film adaptation of the story in episode 4 of Series 2 of ITV's Agatha Christie's Poirot drama series.