Marvel once again poses the question, "What If...?" What if Annihilus had not been defeated in the outskirts of our galaxy, and instead had brought his devastating alien armada to Earth? What if Iron Man had lost the Civil War? What if the Hulk had landed on a peaceful planet, as the Marvel heroes had intended when they exiled him into space? Or Banner had landed on Sakaar instead of the Hulk? Or the Hulk's warrior bride, Caiera the Oldstrong, had come to Earth seeking vengeance instead of her husband? What if Vulcan had become Phoenix? And finally, what if Peter Parker had never come home years ago after following Wolverine to Russia and accidentally killing a friend? This title collects "What If? Annihilation", "Civil War", "Planet Hulk", "X-Men", and "Spider-Man vs. Wolverine".