Everyone thinks Sirius Black wants to kill Harry. Dumbledore sends all of the students to sleep in the Great Hall overnight so that the teachers and staff can search the school. Snape thinks Lupin is helping Sirius sneak into the castle.
Sirius breaks into Hogwarts to find Peter Pettigrew
Date October 31st, 1993
Certainty Stated in canon
Type of Event Wizarding world