It was snowing the day I went to St. Joe’s Emergency Department in Bangor to talk to the staff about working the night shift. Given the weather, most places might have asked me to reschedule. Not the emergency room. They don’t stop for weather, time of day, holidays, natural disasters — or even a writer standing in the wings with her notepad and pen.

The doors are never closed, and by year’s end, according to Dr. Busko, the ED medical director, more than 25,500 people will have come through its 16 routine care beds, three resuscitation rooms, and three fast-track beds.

This night was just one of many.

When I arrived at 7:30 p.m., I expected the place to be packed. I pictured chaos — just like in the movies.

In fact, the waiting room was empty. Noise from a television hanging on the wall echoed down the polished floors as Eva, the ED’s greeter, welcomed me to her space and immediately dispelled any notions about predicting the ebb and flow of ED traffic.

“Nothing is routine down here,” she said, motioning first toward the snowy window and then the empty waiting room seats. “It’s never the same.”

Down the hallway, however, behind the double doors of the ED, another story was unfolding. A patient was in crisis. This was not immediately apparent to me because, except for bells going off and an uptick in movement around the nurses’ station, the ED functions like a well-choreographed dance. Everyone knew their part. Everyone had a job. And if any of the nurses were flustered by the emergency going on around them, it was not evident.

I say “nurses” because most of the activity was from them, which the doctors readily admit.

“Most of the care that happens at the hospital is nursing care,” Busko said.

Once the emergency had passed, Dr. Thomas, an ED physician agreed. “We are a machine that works well,” he said. And then, quite emphatically: “It doesn’t matter which shift (day or night), I rely on my nurses.”

Thomas likened the quieter moments of the ED to the stillness of a chapel at night. That’s when things “seem to be OK, stable,” he said. There are peaks of activity here and there, and although those moments are unpredictable, some patterns develop over time. A rush of emergencies comes between 12-1 a.m. when people are more likely to be involved in alcohol- or drug-related accidents. Another rush comes between 4-6 a.m. when elderly people tend to rise for the day and experience falls or heart attacks.

Meaning: The majority of the world is sleeping between 1 and 4 a.m.

But not the nighttime ED staff. They are there and waiting should you need them.

The ED is almost never completely empty, even though, as on this night, the waiting room might be. It is rare for the board with patient names on it at the nurses’ station to be empty. It is such a rare occasion, the staff has a name for the moment when there are no patients in the ED. They call it “Winning the game.”

During the quieter moments this night, I had an opportunity to talk to nurses individually. Many of them had more than 20 years of experience on nights, beginning when they were raising young children and wanted flexibility during the day. Some of them stayed on nights even after their kids had grown.

“(Working nights) makes you a better nurse,” Nadine told me. Without the hospital’s ancillary daytime staff, night nurses become a tightly knit team and operate like a family. “You have to know your team because they are all you have on nights.”

Shelby, the ED charge nurse, agreed. She said working at nights has made her a “Jill of all trades,” helping techs and cleaning rooms, because there is less support staff than during the day.

Indeed, the staff reduces by half after 3 p.m.

At midnight, there was a shift change, and I met Dr. Daul, an ED physician who only works nights. They call him a nocturnist. Dr. Daul covers 50 percent of St. Joe’s nighttime ED shifts.

“I decided to do nights to — and this seems ironic — to maximize facetime with my children,” Dr. Daul said. Most nights, he is home to have dinner with his family before he goes to work.

Daul acknowledges the risks to working nights, citing literature on its negative health effects — from hypertension and weight gain to increased depression and anger. Daul says he has created a “sleep culture” for himself (he has a special sleeping area in his basement to avoid interruptions from the family) to combat the effects, and he safeguards his downtime in order to protect his mental health.

Daul, by the way, is exactly the kind of person you’d want to meet at the ED in the middle of the night. He is exceptionally calm and relaxed, and he exudes confidence. He speaks in long, eloquent sentences with precise wording.

Although Daul says he has the best gig in the hospital and worries someone will discover how good he has it, I suspect St. Joe’s knows exactly what they are doing by having Daul’s calming presence in the ED at night. Historically, according to Daul, there can be “psychiatric overtones” to some patients at night, and no doubt, his demeanor goes a long way to quell anxieties.

The ED remained relatively calm for most of the night. There was a steady stream of patients, but no more emergencies. In the wee hours of the morning, while most of the city was sleeping, the nurses had a birthday party for Shelby. A rolling hospital cart displayed a tray of yellow and chocolate cupcakes, which the staff ate on hospital paper towels. For a short moment, they shared some time — just like a family.

And then it was back to work, getting ready for the next rush.

Before I left, Dr. Daul came and found me. “We’ve won the game,” he said. He smiled and pointed at the board in the nurses’ station.

And just as Dr. Thomas had said, the space was still and quiet like a chapel. Everything was stable. But even as I left, the nurses and doctors remained, having already “won the game” but ready and waiting for the next emergency.