Marvel's greatest heroes and villains battle for survival across the galaxy on an unknown planet in this prose adaptation of the classic graphic novel. In a flash of light, Earth's mightiest heroes find themselves aboard a mysterious spaceship in an unfamiliar galaxy alongside a ship filled with their deadliest foes. They have been summoned to the strange planet known as Battleworld by an omnipotent cosmic entity, the Beyonder. His message is simple: "Slay your enemies and all you desire shall be yours . . ." The only hope the Avengers, the X-Men, Spider-Man, and the Fantastic Four have now is to prepare for a fight. But who among this murderers' row of villainy poses the greatest threat? Is it the powerful Magneto? The manipulative Molecule Man? The world-eater, Galactus? Kang the Conqueror? Ultron, the robot whose only desire is to kill all life? Maybe it's the enigmatic Beyonder? Or perhaps they should worry about what plans Doctor Doom has up his sleeve. With so many questions to answer, only one thing is certain: the battle royale begins now . . .