I’ve been riding the Red Line in Chicago for twenty-six years, and I like to think I’ve seen everything a train car can hold. I’ve seen a man play a full set on a tuba between Belmont and Fullerton. I’ve seen a woman knit an entire baby sweater on her commute over the course of one winter, and when she finished it, half the car applauded. I’ve seen a wedding proposal, three fistfights, a lost parakeet, and once, at two in the morning, a priest and a drag queen splitting a bag of Garrett popcorn and arguing about the Cubs. What I’d never seen before that Saturday in October was the kind of quiet, deliberate meanness that wears a nice coat and tells itself it’s just taking up its fair share.

My name is Teresa Kowalski. I’m fifty-two years old, and I’m a charge nurse in the emergency department at a hospital on the South Side. I work Saturday days, seven to seven, and I take the Red Line from my apartment in Edgewater all the way down to work, forty minutes each way if nothing goes wrong. Twenty-six years of emergency nursing teaches you a few things. It teaches you to read a room fast. It teaches you that the people who are loudest about their pain are usually not the ones in the most trouble. And it teaches you to tell the difference between a person who’s taking up space because they don’t know any better and a person who’s taking it because they know exactly what it costs someone else.

That Saturday morning I’d gotten a seat near the middle doors of the sixth car, which is my car, the same one I ride every week, because it stops right at the stairs at Sox–35th. I had my coffee in a travel mug and a paperback mystery I’d been trying to finish for a month. The train was about two-thirds full: weekend riders, a few tourists with maps, some kids in Bears jerseys headed somewhere early, a man asleep against the window with his mouth open. It was a perfectly ordinary October morning, gray and cold off the lake.

I was sitting across from him when I first noticed.

He was a big man, broad through the shoulders, maybe forty, and well-dressed in a way that told you he wanted you to notice. Charcoal wool overcoat, open over a navy quarter-zip. Good jeans. Brown leather boots that had never seen salt or slush. He had a fresh haircut and a watch that caught the light every time he lifted his phone. He was scrolling something with his thumb and wearing the faint, satisfied expression of a man who has never once in his life wondered whether he was in anyone’s way.

And his knees were spread so wide that the women on both sides of him were squeezed into half of their own seats.

I don’t mean a little. I mean he was sitting in the center of three molded plastic seats and occupying the better part of all three. His left knee pressed hard against the leg of a young woman holding a toddler on her lap, and his right knee jutted across into the seat of a middle-aged woman with a grocery tote, who had folded herself sideways against the pole like a closed umbrella. Both of them were trying, in the way women have learned to try, to make themselves smaller without making a fuss. The young mother had her son pulled tight against her chest and her own knees pressed together and angled toward the aisle, and still that big knee followed her, sitting heavily against her thigh as the train rocked.

I watched for two stops. I told myself it might be an accident. Some big men honestly don’t notice. My own late husband, God rest him, used to sprawl across our couch like a dropped coat and was always genuinely surprised to learn he was crushing somebody. So I waited to see whether the man would catch himself.

He didn’t. Every time the young mother shifted a fraction of an inch away from him, his knee drifted that same fraction to follow.