I was being watched.

There were two of them. One was white, the other black, but their differences ended there. They were almost exactly the same height—tall. Both had short, impeccably neat hair, and were muscle-bound under their turtlenecks, leather jackets, and gray wool pants.

They had cop eyes. Well, actually I couldn’t see their eyes—the matching aviator sunglasses prevented that. But though I’ve never been convicted of anything more serious than cutting class, I knew they were cops, and that I was under their scrutiny.

By cop standards, of course, it wasn’t really scrutiny. I was on the receiving end of the flat gaze that cops use on everyone except, presumably, their loved ones. They had sized me up in an instant. I wasn’t a threat, I wasn’t doing anything illegal. I was only someplace I didn’t quite belong.

That place was the doorway of 1612 20th St. NW, within spitting distance of the north entrance of the Dupont Circle Metro stop. They were a few feet away, standing in front of Zorba’s Cafe. They watched me as I gazed at a sign taped to the back of the glass door. It wasn’t much of a sign. Just a piece of white paper matted on blue cardboard. From a distance of more than a few feet it would be difficult for passers-by to discern the dot-matrixed words “Washington Police Supply” or the computer-generated sheriff-style badges that bookend the phrase. Underneath, in smaller print, are hours of operation: 11 a.m.-6 p.m. Mondays, Wednesdays, and Saturdays; 11 a.m. to midnight Thursdays and Fridays.

Still under their gaze, I pushed open the door. In the foyer, there was another, smaller sign by the buzzers that announce visitors to the offices, which are upstairs, over Zorba’s. The sign warns that anyone other than law enforcement personnel must have an appointment to gain access to the suite.

Needless to say, I did not have an appointment. When I came back out, the stoic expression of one of my monitors gave way to a small smirk.

The Thin Blue Line has set up shop on the Red Line. Why is still an unsolved mystery.

A Washington City Paper T-shirt will be awarded to the person who can demystify the police property room. Inspired answers will appear in next week’s edition if they reach us by Tuesday. Submit your description, or suggest topics for this column, by writing to: Mysteries, Washington City Paper, 2390 Champlain St. NW, Washington, DC 20009. Our fax number is (202) 462-8323, or e-mail us at Mysterieswashcp.com. No phone calls, please.