Never bet the devil your head

The narrator, presented as the author himself, is dismayed by literary critics saying that he has never written a moral tale. The narrator then begins telling the story of his friend Toby Dammit. Dammit is described as a man of many vices, presumably at least in part due to his left-handed mother flogging him with her left hand, considered improper. Dammit often made rhetorical bets, becoming fond of the expression “I’ll bet the devil my head.” Though the narrator tries to break Dammit of bad habits, he fails. Nevertheless, the two remain friends.
While traveling one day, they come across a covered bridge. It is gloomy and dark, lacking windows. Dammit, however, is unaffected by its gloom and is in an unusually good mood. As they cross the bridge, they are stopped by a turnstile partway across. Dammit bets the devil his head that he can leap over it. Before the narrator can reply, a cough alerts them to the presence of a little old man. The old man is interested in seeing if Dammit is capable of making such a leap and offers him a good running start. The narrator thinks to himself that it is improper for an old man to push Dammit into making the attempt—”I don’t care who the devil he is,” he adds.
The narrator watches as Dammit makes a perfect jump, though directly above the turnstile he falls backwards. The old man quickly grabs something and limps away. The narrator, upon checking on his friend, sees that Dammit’s head is gone (“what might be termed a serious injury”). He realizes that just above the turnstile, lying horizontally, was a sharp iron bar that happened to be lying at just the spot where his friend’s neck hit when he jumped. The narrator sends for the “homeopathists”, who “did not give him little enough physic, and what little they did give him he hesitated to take. So in the end he grew worse, and at length died”. After the bill for his funeral expenses is left unpaid, the narrator has Dammit’s body dug up and sold for dog meat.