The narrative centers on a man who discovers a mad scientist living in a cave near Dalkey, Ireland, who possesses the power to destroy the world. The protagonist, Mick Shaughnessy, seeks to understand the motivations of this scientist, De Selby, who intends to evaporate the world using a substance called DMP. The story operates within a framework of philosophical absurdity, where the protagonist must navigate the bizarre logic of a world where historical figures like Saint Augustine and James Joyce are resurrected or manipulated. The narrative structure is non-linear and relies heavily on dialogue-driven encounters that challenge the reader's perception of reality and time.

Discussion often centers on the author's unique ability to blend high-concept philosophical debate with low-brow slapstick humor. Readers frequently highlight the chaotic pacing and the deliberate lack of traditional plot resolution as defining characteristics of the work. Critics often note that the novel functions more as a series of intellectual provocations than a cohesive story, which can be polarizing for those seeking conventional narrative arcs. The text is widely regarded as a challenging piece of metafiction that rewards those familiar with the specific literary and historical targets O'Brien lampoons. Ultimately, the work remains a significant example of mid-century experimental writing that prioritizes stylistic play over structural consistency.