Carla followed the others into the building. They bunched up at a second set of heavy glass doors that blocked access to the lobby proper. This inner entrance was manned by two more security guards. One stood on this side of the doors, directing the visitors to an automated flatscan camera that took each person’s picture, then spat out a laminated badge bearing the words VISITOR’S PASS and the date and time of the tour group’s arrival. The other guard stood on the far side of the glass door, looking on with a bored expression as visitors who were leaving the building dropped their passes into a machine that automatically scanned and counted them. Eventually it would strip the digital photographs and dates from the badges so that they could be reused.