Expanding runes were taught in 6th year so only Hermione, Zachary, Chastity, and Quincy Nott were able to work. After drawing the runes all the students moved around saying the proper spells. This way, the magic of the runes was attached to many people, not just a few people so if one died the room would stay. The runes took nearly 4 hours, and by the time they finished it was time for lunch.