Robert Bloch. I Do Not Love Thee, Doctor Fell. (The Magazine of Fantasy and Science Fiction 1955)
Sitting down at the computer in a brief interlude from a day gardening in the sunshine I did have the option to re-read the story. but..
The Magazine of Fantasy & Science Fiction, March 2009
Daniel Abraham. The Curandero and the Swede : a Tale from the 1001 American Nights.