The Electric Executioner by Adolphe de Castro and H. P. Lovecraft

A man on a train journey meets a fellow passenger who claims to be transporting a new form of execution device—and also the condemned man himself. As the story progresses, it becomes clear that the inventor is deeply unhinged and the line between victim and executioner is not what it seems. The plot accelerates toward a deadly confrontation in the Mexican wilderness. A tense, bizarre thriller with dark humor and a shocking twist. A tale where madness rides first class.