"Gimmicks Three" is a fantasy short story by American writer Isaac Asimov.
The title refers to what Asimov called "the three well-worn gimmicks of pact with the devil, locked room mystery, and time travel".
On the proviso that eventually he will be forced to enter hell, either as an ordinary damned soul or as a member of the cadre, he is allotted a number of demonic powers, the nature of which are not initially explained to him.
In the story's climax, it is revealed that he has moved back to the time before he had signed away his soul and so he is able to turn down Shapur's persuasive offer, much to the demon's fury.
However, he still had his ten successful years, since deals with Hell can give a person nothing he could not have obtained on his own.