It was first published in the April 1941 issue of Unknown, and can be found in Heinlein's short story collection The Unpleasant Profession of Jonathan Hoag.
He spends much of the story engaged in verbal sparring with the psychiatrist who is caring for him, and in pondering his predicament, trying to figure out a way to prove that his belief is true.
On the final page of the story, the reader discovers that his belief is true; the god-like character "the Glaroon" is behind the conspiracy.
The story has been noted as "both a paranoid and a solipsistic fantasy", containing "the most complex discussion of those philosophical matters that have troubled [Heinlein] throughout these early years [of his career as a writer].
"[2] Gary K. Wolfe describes it as a "classically paranoid vision of the world", and states that the story only qualifies as fantasy because Heinlein does not offer any explanation of "who or what the Glaroon is and what its motives are".