When Voldemort attacked he didn't kill Lily and James. When he met his downfall they mistook Harry's twin as the GWL, they send their son away to the Dursleys but he doesn't quite make it in to the Dursley's loving care. Harry will take Hogwarts and his 'family' by storm and by the time the 'light' realize their mistake it will be too late for them to fix. OOC!Dark!Powerful!Harry.