The Incredible Elopement of Lord Peter Wimsey

An American doctor lives in a remote part of the Pyrenees with his wife who is suffering from a debilitating illness, which the doctor has convinced the local inhabitants is due to witchcraft. A man who represents himself as a powerful magician arrives in the area, and the local woman who cares for the wife consults him for a cure.

This story contains no actual speculative elements, since a crime blamed on witchcraft was actually committed with drugs, and the "magic" with which the detective "removes the spell" is conjuring tricks. However, significant parts of the story are narrated from the point of view of people who believe the events to be supernatural.