The secret entrance has the appearance of a non-working toilet and there's always an out-of-order sign on the restroom door to keep regular people from discovering the hidden elevator. Ironically, in Bengeance Is Mine, Bill Gacks, a normal human plumber, actually fixed the broken toilet. The shop is no longer in active use since the Plumber Headquarters was moved to space. People can move between Earth and the base through teleportation.