The only indication by which he could tell, from his distant vantage point, that I was not fevered was that I wore a mask. And though Sentinel guards did not wear masks (given the scope of the epidemic, we had begun to understand that the masks were not fever-preventative), wearing a mask meant something. It was a visual shorthand that I was fully cognizant, that I understood the distinction. Thus I always wore a mask outside, to mark myself as unfevered.
