On hearing the title A Voyage to Arcturus, one might picture an astronaut strapping themselves into a rocket and flying into space for a swashbuckling adventure. Nothing could be further from what this book actually is.

Voyage is in fact a fascinating, bizarre, bewildering, and thought-provoking sort of acid-fueled Pilgrim’s Progress: a philosophical allegory told through the frame of a psychedelic gender-bending journey to an alien planet.

After a terrifying séance, the protagonist, Maskull, is offered the chance of an adventure on a different world. He agrees, and the reader follows him on his blood-soaked path through lands representing different philosophies and ways of life as he searches for the world’s godhead, Surtur. Or is it Crystalman?

Voyage features fiction wildly ahead of its time, and is hardly classifiable as either science fiction or fantasy; one might even say that the book is better approached as a philosophical work than a straightforward narrative. It’s not a book for a reader seeking simple fiction, but rather for a reader seeking a thoughtful, imaginative, and totally unexpected exploration of philosophy and of life.

Decades ahead of its time, Voyage was praised by contemporaries like C. S. Lewis and J. R. R. Tolkien, and by modern authors like Clive Barker and Alan Moore. Many modern reviewers consider it a masterpiece of 20th century fiction and the work of an underappreciated genius. A century later it boasts a significant cult following, having inspired movies, plays, albums, and even operas, as well as a modern sequel by famous literary critic Harold Bloom—the only work of fiction he ever wrote.