The auction assistant leads them through a series of winding corridors and up the stairs towards the surface, bringing them out at the same spot Cain exited before, the standard item appraisal area.
Once they're free of the restrictions on abilities, Cain changes back to his human form and steels himself for the inevitable chaos of Tortuga on Auction day. The interior of the auction house is so packed at this point, as everyone tries to get a last minute registration or ticket to the main auction that not only are they not noticed, they almost need to shove people out of the way to leave.
Only the fact that their leaving creates another open space to move into convinces people to let them through, and they slowly inch through the crowd, Cain in front and Aggramor in the rear to keep everyone together.