On the evening of Halloween 1981, a butterfly flaps its wings and Fate's carefully created plan shatters. Lord Voldemort attacks the forces protecting Longbottom Manor and at the same time in Godric's Hollow, the origin story of one Harry James Potter changes. Twelve years later, a retired duelling champion is sent to clean up the mess. BWL!Neville Slytherin!Harry Mentor!Flitwick