Harry Potter and the Cauldron of Myrddin

Almost two years after the war, Harry Potter and his friends are invited back to Hogwarts for their final year. The boy-who-lived anticipates a boring school year but he doesn't expect the presence of an scarred enigmatic witch who possess power beyond thought. Mixed in with a school play and a pink potion that keeps popping up, Harry's last year is nowhere near uneventful.