Cannon Chapter Eight introduces the teachers, and the robbery. Cannon Chapter Nine has Draco, Hermione, the fake duel, and the Cerberus. Here we are going AU fairly strongly again. Because Harry fled the Hall, our introduction to the teachers is not their teaching style, but their glimpses of Harry. Our introduction to the students is not shaped by Ron, but rather Hannah (who would someday in the Cannon universe become a prefect) becomes concerned for their missing year-mate and convinces Susan to help her look for him. The Cerberus remains undiscovered, and Harry never learns of the robbery attempt. Draco has no reason to challenge Harry to a fake duel.