A castaway on a deserted island finds himself inexplicably drawn to a mysterious, recurring apparition. Morel's existence is a puzzle, a phantom presence that seems to repeat the same actions and interactions endlessly. The protagonist, isolated and desperate for understanding, attempts to unravel the nature of this phenomenon and its connection to the island, facing the existential dread of his own solitude and the unsettling implications of Morel's perpetual, yet unreal, existence. The narrative unfolds through the castaway's journal entries, offering a fragmented and introspective perspective on his investigation.

The collection, particularly 'The Invention of Morel,' is widely recognized for its prescient exploration of themes that foreshadow later science fiction and philosophical inquiries into virtual reality and consciousness. Critics have lauded Bioy Casares for his elegant prose and his ability to craft intellectually stimulating narratives that linger in the reader's mind. The novella's influence is noted in its thematic resonance with later works that grapple with simulated realities and the nature of perception. The stories collectively offer a profound meditation on isolation, memory, and the elusive boundaries between the real and the imagined.