At the start of the game, you learn that the Death School has disappeared from Ravenwood. There's a student helping Death students with getting cards for the school.
After I got to around level 15, I finally found out what really happened to the school. It seems to have fallen into this crazy place.
Inside the building, I found a hunchback character giving the same cards that the student was giving out. The Headmaster told me to keep it a secret at the moment. Have to see what happens when I continue on.