Harry Potter and the Sorcerer's StoneChapter 1
Voldemort's Defeat and Harry's Survival
Voldemort kills James and Lily Potter but his Killing Curse rebounds on baby Harry, leaving a lightning scar and causing Voldemort's disappearance; Dumbledore, McGonagall, and Hagrid leave Harry with the Dursleys.
Outcome
Harry becomes the 'Boy Who Lived'; wizarding world celebrates Voldemort's downfall.