Arc 8The Monster at Hogwarts
Harry pursued an Animagus transformation while Black Ginny attacked the Acromantulas in the Forbidden Forest. A monstrous creature then struck Hogwarts during a Quidditch match, and the professors fought it as Snape investigated its origins.
- After Harry caught the Snitch against Hufflepuff, Dumbledore told him that Horace Antonio had been struck by a jinxed Bludger and remained unconscious.
- Hermione suspected Horace Antonio was the new Heir of Slytherin, while Ginny learned from Black Ginny that he would recover from her jinx within a month or two.
- Harry chose Care of Magical Creatures and pursued an Animagus transformation, seeking magical death's-head hawkmoth pupae in Knockturn Alley.
- Fred and George celebrated strong profits from their joke products, while Black Ginny prepared to sever her connection to the Diary and attacked Aragog's Acromantula colony.
- During Hufflepuff's match against Ravenclaw, a giant spider-woman creature smashed through the stands and attacked the professors and students.
- McGonagall, Snape, Sprout, and Flitwick fought the creature as Harry and Neville remained conscious, and Snape went into the Forbidden Forest to find the ritual site.
- Snape confronted Hagrid, who revealed that Aragog's colony had moved after the Wolf Demon destroyed its nest, and Snape found a long, fiery-red hair near the area.
- Sprout and McGonagall trapped the creature in metalized Thorn Vines, but it corroded through them and collapsed into a bloody puddle as Harry and Neville retched.