Caught between realities, a mathematician, a book dealer, and a mobster desperately seek a notorious book that disappears upon being read. Only the author, a rakish sci-fi writer, knows whether his popular novel is truthful or a hoax. In a story that is cosmic, inventive, and sly, multi-award-winning author Lavie Tidhar (Central Station) travels from the emergence of life to the very ends of the universe.

Delia Welegtabit discovered two things during her childhood on a South Pacific island: her love for mathematics and a novel that isn't supposed to exist. But the elusive book proves unexpectedly dangerous. Oskar Lens, a science fiction-obsessed mobster in the midst of an existential crisis, will stop at nothing to find the novel. After Delia's husband Levi goes missing, she seeks help from Daniel Chase, a young, face-blind book dealer.

The infamous novel Lode Stars was written by the infamous Eugene Charles Hartley: legendary pulp science-fiction writer and founder of the Church of the All-Seeing Eyes. In Hartley's novel, a doppelganger of Delia searches for her missing father in a strange star system. But is any of Lode Stars real? Was Hartley a cynical conman on a quest for wealth and immortality, creating a religion he did not believe in? Or was he a visionary who truly discovered the secrets of the universe?

'Brilliant and bizarre, Lavie Tidhar's The Circumference of the World is many things - but fundamentally it is a love letter to the Golden Age of science fiction, whether or not it deserves it (it does), as well as a love letter to its writers, whether or not they deserve it (they don't. Well, mostly.).' - Molly Tanzer, author of Vermilion and Creatures of Will and Temper