I FIND THE FIRST day of anything tough—first day of school, first day of camp, first day of the year. My tendency is to view the unknown future more with trepidation than joy. And now I could add to that list the first day of work.

As I walked toward New York’s 5th precinct, a hot, muggy wind off the East River sent trash scurrying down the gutters and wafted to me the scent of garbage rotting in black plastic sacks awaiting pickup. Abandoning me, the wind raced on to seize the American flag on the front of the station house, gripped it, and set it twisting and snapping like a maddened whip.

The four-story building that housed law enforcement for the part of New York City known as Jokertownoil, sweat, and vomit there was the distinctive burnt-nuts smell of very old coffee and very fresh donuts in the air. My stomach gave a growl. I had been too nervous to eat breakfast. Maybe this is how cops become a cliché, I thought. I longed to go in search of the donuts, but instead followed Beastie into the briefing room.

Beat cops were settling into chairs. Behind the podium was a middle- aged Asian woman with an oval face and worried dark eyes. Her name tag said CHOY. Behind her was a large and detailed map of Jokertown and a bit of Chinatown where the two intersected. There were wanted posters and updates from the FBI, SCARE, and other law enforcement agencies.

I took a chair in the back.