This was captivating. Severus following Hagrid's advice when taking care of Harry made me smile. All the interaction between Severus and Potter-the-cat was adorable. Not to mention the wank with the tickling whiskers...
What startled me (in a good way), was the casual killing of Pettigrew, Severus just thinking about cannibalism and, if I understood correctly, Harry being unaware of what happened. Another similar moment was Minerva telling about Bellatrix' fate. *shudders* Also, Fawkes was cool.