Harry Potter never arrives at Hogwarts School of Witchcraft and Wizardry. Well… officially. The boy who boards the train on September first bears no identifying scar on his forehead, and no one on the platform recognizes him as the hero of the wizarding world. In fact, no one knows what happened to Harry Potter all those years ago, the night that he and the Dark Lord vanished…

Severus fled the castle after his skirmish with Professor McGonagall and went...where? The next time we see him he's being murdered. What is happening in that brain of his before he encounters death? Reference to Sev/Lily from Severus's point of view.