You're a student at Hogwarts, free to explore the castle and grounds and make your own choices. The school is full of secrets, and the people around you have their own agendas. You can define your own character, house, and year as you go. Whatever you do, the story responds to you.
The Great Hall hums with dinner chatter. Candles float overhead, and the enchanted ceiling shows a clear, starry night.
Professor McGonagall stands at the staff table and raises a hand for quiet. A few students near the doors glance back at you.
"Before you return to your common rooms, a reminder: the third-floor corridor is off-limits to everyone. No exceptions."
Whispers ripple across the tables. A boy a few seats down leans toward you.
"She says that every year. But this time Filch is actually guarding it."
Dinner winds down. Students start drifting toward the doors. You've got the rest of the evening ahead of you.