Worlds collide when Peter Parker, the original Spider-Man, finds himself stranded in the Ultimate Universe. On this alternate Earth, Peter Parker's not around any more - in fact, he's been replaced! How will the arachnid icon react to his successor, Miles Morales, and how is he possibly going to get home? Mysterio's meddling has left Peter stranded. Now, he'll need the help of an eerily similar team of Avengers to help him defeat the villain, and make it back to Earth-616!