 Which word doesn't describe the security guard?
Yes, it'll be pretty obvious it must be a time machine. That means you either carry a small time field with you, or you are catching a small increment of time from the main field. Some of them can be decoded to stationery shops, fountains, and the like. You wouldn't care if you saw a man in a leopard-skin suit; you'd figure it was some part in a play and let it go. The museum's closed, but I'll be glad to let you study whatever you need for realism in your role. "Thanks," you mutter, wondering what kind of civilization can produce guards as polite as that.
 curious
 knowledgeable  friendly  curious  helpful