Invaders of the Forbidden Moon

The moon that kills all who approach. Io, outermost sentinel of Jupiter, wraps itself in a veil of cosmic violence, an energy barrier that has destroyed a thousand ships and a thousand dreams. But humanity has never been good at accepting "no." Gallun's 1940s space opera traces the desperate quest to breach Io's deadly shield and discover what lies beneath. What waits on that scarred surface? What power built such a defense, and what happens when at last someone breaks through? This is early pulp SF at its most electrifying, when space still felt like a frontier of impossible wonders and terrible dangers. Gallun writes with the raw excitement of a writer who believed the cosmos belonged to those daring enough to reach for it. A wild ride for readers who want their science fiction with high stakes, ancient mysteries, and the thrill of first contact.