One of the most popular, prolific, and important science fiction writers, Robert Silverberg is given penetrating analyses by major scholars and critics of the genre. Extending beyond the conventions of popular culture and pulp science fiction, the seven essayists assess Silverberg's body of work as being manifest of the modernist literary tradition, exploring techniques, such as irony, and themes, such as the fragility of identity, utopia and dystopia, and spirituality and transcendence.

Noted Silverberg scholar Thomas Clareson contributes an overview of Silverberg's literary career from his first story published in 1954 to the present, and the editors provide a bibliography of his fiction and selected secondary studies, referring to Clareson's definitive bibliography. The trapdoor metaphor used in the title relates to an observation by critic Russell Letson on the complexity of reading Silverberg, which he compares to an experience of one of Silverberg's characters: What seems to be a firm foundation for reality may in fact turn out to be a trapdoor.