On jandered my escort, past various office doors—all mahogany, all notably missing nameplates; presumably, if you didn't know where to find the office you wanted, you just plain didn't belong here. Another couple of turns, and another double door; this time floor-to-ceiling transpex with some kind of chromatic coating that made the doors look like huge opalescent soap bubbles. Again the doors swung back as we approached and again closed silently after us.