Harry had told her that's what the aurors called the DMLE floor in the Ministry given its maze of cubicles, offices, conference rooms, interrogation rooms, labs, etc. etc. The tangle included the prosecutors offices. Hermione had applied for an internship in the auror warrant office wherein she'd meet many Wizengamot members and liaise with the aurors. She hadn't heard back yet on her application, but Harry was already planning their lunches and all the cases they'd work together.