There are no locks on the lockers or the bathroom stalls at Trinity. This lack of locks is a symbol of the lack of privacy and security at the school. If you leave something in your locker and it gets trashed or stolen, it's your own fault. Although many of the students have a personal code of honor and would never steal from a classmate, many others don't. This seemingly small detail does a lot to enhance the Gothic mood. (See "Genre" and "Writing Style" for more.) Although locks can be used to confine and isolate, in this novel taking away the locks confines and isolates.