The Conversation with the Man Called Al-Mu'tasim: A Game of Shifting Mirrors is a non-existent novel supposedly by an Indian writer named Mir Bahadur Ali, referenced in the story The Approach to Al-Mu'tasim by Jorge Luis Borges (title in Spanish: El acercamiento a Almotásim). Borges's short story takes the form of a commentary on the fictional work, describing Conversation as a rewriting of the earlier book The Approach to Al-Mu'tasim. Borges states in the story that though both books have been popular, the first had an original printing of 4,000 copies and was never reprinted, while the second has often been criticized for poor writing and for its obvious allegory to the quest of finding God. He further states that The Conversation with the Man called Al-Mu'tasim was published in 1934, the second book is by far the better known, having been reprinted several times and translated into English, French, and German. Such minute details have led many readers of the Borges story to assume that the book he is "reviewing" is real, when no such book actually exists.

The original Borges story appears in his anthology Ficciones or in Historia de la eternidad.

The imaginary work is essentially a detective story about a law student in Bombay. After unexpectedly committing a murder, he becomes an outcast among the lower classes of India. Through his dealings with people he infers the existence of a perfect man, whom he calls Al-Mu'tasim. He believes Al-Mu'tasim has affected others in particular ways through interaction, as though some perfection was "rubbed off" onto them. The student becomes obsessed with finding and meeting Al-Mu'tasim.