I’ve always been fascinated by the idea that when I go to sleep, something that doesn’t always come easily, there is another world out there, and it’s filled with people who are working, protecting, entertaining and, yes, having fun. (I know, I’m usually in my pajamas by 8 p.m., too.) This year, I want to learn more about these people working (or enjoying) the night shift, and I begin with a night following my city’s own: the Bangor Police Department.

People outside of Maine know the BPD as the one with the Duck of Justice and witty Facebook posts. When the Washington Post wrote about the BPD’s Facebook page in 2015, reporter Sarah Netter said, “The most popular hangout in Bangor, Maine isn’t a restaurant or a bar. You can’t find it on a map. But you can find it online. Bangor Police Department’s Facebook page has become must-read material for legions of fans across the country who log on for Sergeant Tim Cotton’s comedic musings.”

Netter is right about Sergeant Cotton’s musings, but she is wrong about “the most popular hangout.” As I’d soon learn, you can’t actually identify the “most popular hangout” in any city until you’ve cruised through town in a police car after the bars close.

I arrived at the police department at 8 p.m. (please see above about the pajamas thing) on a Saturday, and Patrol Sergeant Jason McAmbley came into the lobby to greet me. He was mid-sip of his coffee when I asked how he was doing.

“Just waking up,” he said.

I’ve met McAmbley before, when he was the Community Relations Officer. He is tall, gregarious and funny. But at the beginning of this night, he was more subdued, like you’d expect a co-worker to be when he is standing at the Keurig at 7 a.m.

A few cups of caffeine later, McAmbley was making his jokes about firemen getting to sleep, and we were off and running.

We spent the first hour in a darkened room where dispatchers take your emergency calls 24 hours a day, 7 days a week, 365 days a year. Three women wearing headsets sat in front of over-sized computer screens and took calls, some of them urgent, some of them about raccoons in the yard (don’t do that). The women’s voices were unwavering and calm. This is where most of the police work begins, with these calls.

Next, we got into a patrol car. (Note: McAmbley was wearing a bulletproof vest; I was wearing an LL Bean puffer vest.) The city streets were now emptied of the usual dinner-and-a-movie set, who were already home in their pajamas. The streets, in fact, seemed serene, and all the restaurants and businesses that aren’t bars stood like shells of their daytime selves. Their storefronts glistened from one or two carefully placed lights as we drove past.

So did many of your homes. A light on here or there meant those families were probably asleep. But McAmbley and all of his patrol officers had your back. We patrolled areas where the city has had disturbances, and sometimes, if something looked amiss (a window open in a vacant property, a car with lights on in an empty field), McAmbley shined his light to make sure everything was okay. He did this for businesses, too, often cruising through parking lots and behind, near dumpsters, to ward off trouble.

As it got closer to bar-closing time, McAmbley moved to downtown. He often foreshadowed this moment earlier in the evening, like a weatherman might talk about a storm, or a teacher might talk about a school day that will fall on Halloween: It was coming. It would be big. And, no, he couldn’t tell me what to expect. Each night is different.

Then, one by one, the bars opened their doors and a sea of people spilled onto the streets. That’s pretty much exactly how it looked: they spilled out. Of course, many of the people had been drinking, and I realize some of the bar patrons resented the police presence. But from my vantage point in the passenger seat, McAmbley was there to protect you — from others or yourself. He watched to make sure no one got hurt and, importantly, that no one who shouldn’t got behind the wheel.

“Don’t get in that car,” McAmbley mumbled under his breath. And then, “Good, he’s getting in a cab.”

Throughout the night, McAmbley also made routine traffic stops, answered concerned citizens’ questions and responded to a medical emergency. During one moment of down time, McAmbley called his mother. We never got donuts.

We got back to the station at around 3:00 a.m. Other officers were also returning from their patrols and were busy writing up reports or reviewing videos from their stops.

“These officers make it very easy to be their supervisor,” McAmbley said. “They do all the work — responding to calls, initiating calls and doing paperwork, all while staying awake all night.”

Their average age? Just under 30.

Before dawn, fatigue set in for me, and McAmbley sent me on my way. Earlier I had joked with McAmbley that I’d be snoring while he was still working. That definitely ended up being the case. As my head hit the pillow at 5 a.m., I thought about what I had seen: officers serving and protecting throughout the night while the rest of the city slept. And as my eyes closed some time later, I was glad to be among the sleepers.