"Philomel Cottage" is a short story by Agatha Christie which was recently identified as the answer to a story-ID question on our site. After seeing it there, I read the story in full - it's only 10 pages, freely available online, and thoroughly worth the time.
At the end of the story,
Gerald Martin, or Charles Lemaitre, is found dead in his chair.
This does not seem to fit the dream Alix had before:
She saw her husband lying dead and Dick Windyford standing over him, and she knew clearly and distinctly that his was the hand which had dealt the fatal blow.
But what's less clear is how he actually died. Alix has just told him a story in which
she plays the role of the "female Bluebeard", making him think that she poisoned his coffee. But it doesn't seem that she actually did such a thing: she was instead waiting for Dick Windyford to come and save her. So, what really happened? Did he simply die of fright?