Without the magical suppression cuffs, Draco was able to use wandless magic, immediately choosing to silence their footsteps.  They quietly began maneuvering through the hall, following the winding path.  Nothing made sense about the layout, though maybe that had been the intention.  They assumed they were still in D.C., given Dolohov’s confidence Hermione would respond.  Scott had said if they got above ground, he would be able to figure out where they were.  They just had to escape first.