There's a crack in his wall. It's been there for some time, and for some time, things in Peter's life have been slowly slipping away. It's only when he has lost his parents, and his uncle, and any hope of a normal life, that he realizes what he should have seen all along. Peter Parker's life doesn't make any sense, and it hasn't for a very, very long time.
"Lily and James, Sirius, how could you - " 'how could think I would betray them' But the words never left Peter's mouth, and he was never given the chance to explain. The world exploded. AU, Peter Pettigrew doesn't betray the Potters, but that doesn't stop the world from spiraling into chaos.