After Sunny received her mysterious note when she was in lecture with J.D., her and Howie, Denise and Katie visit the broom closet. There, a shelf slides away revealing a man sitting at a desk. The man is Janitor. He lays down some ground rules for their behavior at Sacred Heart. He tells them that they are not allowed to wrong him or enter Brain Trust headquarters. Janitor asks if anyone likes Dr. John Dorian, to which Katie says yes, and he kicks her out of his office. Ted enters and notifies Janitor that his next appointment - a man with a raccoon - has arrived. Janitor then kicks the interns out of his office. (thetvdb.com)