It’s 3:20 in the afternoon, and I’m sitting in a South Loop spot called the Scout Waterhouse + Kitchen. It occupies a big space at Wabash and 13th Street, the kind of place you might go for trivia night or to sing karaoke. On weekends, bands occasionally play here. Right now, though, it’s nearly empty. Shafts of sunlight fall in dusty wedges from the windows. Two women sit to my right at the bar, wearing vintage dresses, each a different color of a kitchen from my 1970s childhood. The first woman: bright red hair, thick glasses, a sleeve of tattoos on her right arm. The second: some blue hair, partial head shave, silk scarf, and a very nice men’s wristwatch. Drinking bourbon as they parse the menu. They hear each other, but I can’t say they listen. I do, though. I really listen.

“Everything is share plates now,” the woman in glasses says. “The whole world comes on share plates.”

“Don’t get the Brussels sprout salad,” says the woman with the watch. “Seriously.”

A pause. They continue reading the menu. The glasses woman affects a voice, makes a mock order of an item not even on the menu: “I’ll have a share plate of pork belly.”

The watch woman looks up from her menu. “Are you ordering?”

The glasses woman answers another question altogether. “Sprouts don’t interest me.” Then she says, “No, I’m not ordering.” She reads more menu, then muses: “Can you imagine your father ordering pork belly?”

“My dad loves bacon.”

“So you’re saying he would order pork belly?”

The watch woman peers at her. “What?” A pause. “My dad bought and sold futures. So he was, like, you know, familiar with pork bellies.”

Another silence.

“I’m just going to have the sprouts,” the watch woman says.

“You just told me don’t get the sprouts.”

“Because I order sprouts every time. That’s what I’m getting, and we don’t need two plates of it.”

“Two share plates,” the glasses woman clarifies.

So much shorthand, so much history between them, and still a measure of disconnection.

We sit like this for an hour. They share the sprouts. They talk about fabric, which turns out to be their business. “Silk,” one of them says, “is a war crime.” Before I can figure that one out, they depart for a museum of some kind. We never make eye contact. I never hear their names.

Eavesdropping on strangers is an underrated pleasure. You find yourself sitting in the middle of intimacies, tensions, routines. Stories, incomplete and provocative, flare from half-expressed circumstances. Somehow, on the share plates of the overheard, people are funnier, more complex, more verbally adept than you could have ever expected. You never know when you might catch 30 seconds of The Glass Menagerie while waiting for a barista to complete your chai.

I’m not a people watcher, which is hardly an urban sport anymore. People watching is the mild dish soap of social observation. Better to get near enough to draw inferences, to sink yourself into stories you never imagined. I recently spent three days in and around the Loop hardly saying a word, just listening in on various constellations of humanity. I got close enough to hear, and I don’t hear particularly well. So really close. I pressed in. I violated space and stole words from the air. Fairly or unfairly, I discerned the lives of the people I encountered in their smallest measure. All the while pretending to look for a street sign or scroll through my phone.

Eight million stories in New York City? Hyperbole. I listened in — sometimes for just a minute, sometimes for an hour — on maybe 600 conversations. And from that I gleaned 84 fairly autonomous Chicago stories. That’s an exact count. I kept a notebook.

As I walk north on State Street, near Adams, a lanky old man in a sky-blue suit marches toward me, lecturing backward, shouting a little over his shoulder to a clutch of younger associates. He’s not waiting for his audience to respond. He makes his pronouncements on the fly. As he passes, I catch a couple of full sentences: “So, after they leave, that’s absolutely zero water. Zero. Nothing in reserve!” He looks back at the associates. “And that, friends, is a checkmate!”

Maybe that is the climax of his story. He sure seems to think it’s a payoff. I want to hear more about these waterless fools that the blue suit is so dismissive of — how they cut their own throats and squandered resources! — but he’s headed in the opposite direction. I don’t follow. You can’t easily turn on your heel when eavesdropping. Stories bolt past you all the time.

At first I thought I’d be able to hear best when I followed people, as if their words might drift behind them like cigarette smoke. But words have no drift. They’re meant to find a landing place in the mind of the intended. The best way to eavesdrop, I discovered, is to walk parallel with the targets, keeping pace with them, lagging just at their shoulders. I focused on their mouths, their postures, their expressions, as I walked alongside.

I learned certain things: Old people keep their eyes front and down. They watch for trouble, respect their own stiff necks, speak a little softer than they ought. People on phones speak loudly and upward. They walk as if stepping over everything on the street, the way we avoid dog turds. They merely endure the physical world.

Passing by one-half of a phone conversation, I’d pick up snippets:

“I’ve told you many times, and I can repeat it now because for some reason you are not hearing me: I’m never sitting on the mezzanine again” (Michigan and Monroe).

“Why are you so unwilling to make this thing family friendly? For God’s sake, it’s a zoo for babies, Michael” (outside the Chicago Athletic Association Building on Michigan).

“You remind me of Doc Holliday. … No, from the O.K. Corral. … Right, exactly, you fucking loser” (in the doorway of the Harold’s Chicken Shack on South Wabash).

People don’t talk as much on the move. When you’re jostling shoulder to shoulder beneath the L on Wabash or cheek by jowl along Michigan Avenue, it can be impossible to make yourself heard. The pace of progress won’t allow it. Eavesdropping is pointless.

Better to look for the inevitable pauses that come when people cross from one environment to another — entering an office building, waiting for a table at a restaurant, pausing at a street corner for a break in traffic. These moments of transition, these physical lulls, are the points when people can be best overheard.

Crosswalks were the spots where I first started distinguishing the voices of those who talk a lot while saying very little.

Two women on the corner of Wacker and Wells, just before noon, with the river in sight, looking for a moment to cross the street. They are maybe 24. I pick up in the middle of their conversation, which they carry on without once looking at each other.

“It’s like being an illegal alien,” says one. “Sexually, I mean.”

They have to be loud because of the traffic. They engage in a kind of practical shouting. Here and there, heads turn.

“I know,” replies the second. She thinks for a moment, then says: “Wait. Like a sexual alien?”

An old woman, standing to her left, laughs without looking at her. Which makes me laugh.

The second woman notices and takes a sidelong glance at me, but I am behind sunglasses, the eavesdropper’s best tool: Take away the eyes and no one can see you listening.

“Totally,” the first woman says, pushing her own sunglasses up her nose. The blare of horns rattles up the boulevard.

Now the second one: “I don’t know.”

“Don’t know what?”

“I don’t really know what you mean. How is that illegal?”

“Oh Christ. OK. It’s like you’re in a foreign country and you shouldn’t be there sexually.”

“But you are. And at some point you’re going to get kicked out, right?”

“Oh Jesus!” says the first woman, turning in frustration. “Did you take even one single class in college?”

The light changes. They proceed.

One night, I find myself pinned in the corner at Cerise, a rooftop bar 26 floors above North Wabash, standing next to a woman — early 30s, bespangled in gold: bracelets, rings, head wrap — who is speaking to two friends. A blockish guy in a tracksuit, wearing sunglasses at 11 p.m., hovers nearby. I can’t tell if he’s with them. Maybe he’s eavesdropping, too.

Wheel-rolling her hand in front of her, the woman describes an evening on a recent vacation. “They train you. First your elbows, then your knees. You gotta spring up! You take your life in your hands going to a place like that.”

It might be a story about a bungee jump. I can’t tell.

“Did Antoine do it too?” one friend asks.

She shakes her head no. “But then I stuck it!” she says. Hoots of appreciation.

“I knew it!” the other friend exclaims.

“You did? Holy shit!” says the first friend.

“I stuck it! Oh yeah,” she says. “Turns out your girl can throw an ax!”

“Damn!” says the guy in the tracksuit, echoing my thoughts.

“I threw that shit all night after that. All night.” She shakes her head. “But Antoine couldn’t do it. Not really. He threw the ax too hard. He tried one-handed, but then he quit.”

“And you were drinking too?”

“I told you,” she says. “It’s a bar. You throwing axes, so you know you drinking.”

“Always be drinking!” tracksuit adds.

An hour later, I’m on the rooftop lounge of LondonHouse. Up here, the crowd is split into two groups: those sitting in padded lawn furniture arranged to appear indifferent to the view of the river, and those standing, mostly shoulder to shoulder in pairs, staring at the lit-up migrations of the city below and the blue guts of Trump Tower across the river. Shouts, murmurs, house music. And words. Gobs of words, forming sentences and settings, conduct and conflicts in the lives of the boozy speakers.

In a group of eight sits a young woman, maybe eight years out of college. Black bangs, little gray sweater pulled tight around her shoulders, speaking with her friends. I can’t hear the others well above the music and chatter, but she is loud and clear.

She describes a Tinder date: “He gets out of the Uber, and he’s all in Cubs gear. Head-to-toe Cubs. He’s got the big C, right? The hat. Jersey. Gloves, even. And I look at him for the longest long time, and I say, ‘Big soccer fan?’ ”

It’s a good line, delivered well. Four of them laugh.

“And he looked really hurt,” she continues. “He’s not the dumb-blonde type either. He’s no Brett from Champaign. He just legitimately didn’t get me.”

“He wasn’t what?” one of the friends asks, holding a finger in her ear.

“Not an idiot,” the storyteller says. “He just couldn’t think ironically.”

One of the guys with them says something I can’t hear. She gives him a look, tilts her head. “You mean like fires?” she asks. Then she leans forward, laughing. “No, not pyro. No, no. Pyronic? Is that what you … No.” She takes a deep breath. “Ironic,” she shouts.

“You gotta have irony,” another woman says.

“I know, right?” says the storyteller. “You gotta!”

The date was over after that, she relates. “We couldn’t last an hour. I handled it all wrong. He was so sincere. I left pretty much right away.”

The whole pack of them nod in understanding.

After that, the rooftop is a pastiche of fragments. Hot clumps of sentences, bits of pseudo-wisdom — each from a different source, each aimed at a different target, each riding the twin rails of insight and meaningless folly.

Consider these three quotes I recorded in my notebook at LondonHouse:

“You can sell anything. Like at a university, depending on how young they are, they’ll go for anything.”

“Look at this place. Everybody’s got creepy cable sweaters and no tits at all.”

“In a way, everything is overdue before it’s trending.”

You can’t argue with these statements. Not when you’re eavesdropping. There’s no one to argue with. No one is talking to you. I quickly gave up the urge to interject. I just learned to be acute in my listening, accurate in my recording, and content to leave the judgment for later. In the great maw of human chatter, true wisdom is a rare gem.

Just after lunch one day, I happen across two men sitting in Kasey’s Tavern, a strapping sports bar on South Dearborn. They’re wearing conference badges that flash their names. The younger one sips an energy drink. With ice. The other, vodka. With ice. They’ve slipped out of a daylong meeting for a break.

“Don’t loosen your tie.”

“Oh, OK.”

“I’m serious.”

“OK, then.”

“Never loosen your tie while the sun is up.”

“What?”

“That’s Rule 1 in these things.”

“Rule 1?”

“Maybe it’s Rule 7. I don’t fucking know.”

“Rule 7, OK. Is that a Chicago rule? Or is it a …”

“I don’t see anyone else wearing a tie. Do you? It’s too warm out.”

“What’s Rule 2?” A pause. “Seriously.”

“How do I know Rule 2? Just don’t loosen the tie. You’ll fucking regret it later.”

Over breakfast the next morning, at the Protein Bar & Kitchen on Lake Street, I pick up more knowledge. A very pregnant woman is quietly telling her also-pregnant sister about her visit to Austin, Texas. I can’t make out anything all that clearly, except these words: “A walk without Travis is a walk I don’t want to walk.”

The statement echoes across the empty restaurant. The woman declares it firmly enough that it sounds inarguable. Wise, even. Staring into her laptop, her also-pregnant sister seems to understand the sentiment precisely. “I hear you,” she says solemnly, like a witness at a sermon.

And with that acknowledged, they are quiet, preparing for their upcoming day, not saying another word about this Travis or who he might be.

I’m left trying to figure it out. A dying friend? An excellent dog? Some wizened uncle? Damn the pregnant sisters, leaving me hanging at Protein Bar.

The pursuit involves some inherent risk — the possibility of discovery and discomfort. But if you want to capture more than stray shouts, you have to push in at times. You have to get a little too close, angle yourself in the conversational vapor trail of people you have no business following, then work to fade into the wallpaper.

One morning in the Palmer House, on the bottom-most lobby level, a guy, maybe 28, steps off the elevator with a woman, a little older, the two of them saying goodbye to someone they’d left behind in the elevator.

“Did he actually say ‘namaste’?” the guy asks once the doors shut.

“Yeah, he really did,” the woman says with a laugh.

“Dude, yoga sucks!” the guy shouts to the departed, now on an upward trace of the elevator. It was a kind of performance line. He must have known someone would overhear it.

A little too suddenly, he and the woman are both gone. I’m locked in: I want to hear more.

So I take a deep breath and follow them around the corner and into a passageway that, it turns out, dead-ends into the glass wall of a coffee shop. That’s the space where the couple now stand in an unusually intimate posture. They are truly looking into each other’s eyes. The woman — she’s wearing a blouse with a graphic of wild horses — reaches out to touch him on the shoulder. “Don’t say that,” she says softly.

Holy shit, these two are in love. It feels undiscovered. Have I stumbled into the grip of a secret romance? No one knows about it but them. And now me.

I don’t know whether to stop or keep moving forward. I’ve missed some intermediate exchange, some opportunity for a kiss at 9:14 in the morning. I pick up the word “worry.”

“Don’t say it around Raphael, you mean,” he says, sighing.

Just then the woman spots me over his shoulder. Her eyes bore right through the interloper. “C’mon,” she tells the guy, and they move along.

I’ll never know the circumstances of their relationship. Never know who Raphael is. Eavesdropping doesn’t impose dramatic structure like that. Characters never exit on cue.

You can observe much in the friendships you happen upon. Real friends are earned by a thousand conversations. They finish one another’s sentences. They laugh for one another, suss out the truths available on an unseasonably sunny day.

Outside the Daley Center, in the grip of the farmers’ market, two men eke the last warmth out of fall. One is in his late 30s. He has his tie off, shirtsleeves rolled up. On his lunch hour, lamenting his wife’s reaction to a particular house he wanted to buy in the suburbs. He’s not angry. He’s more miffed, puzzled, disappointed.

“Squatty,” he says. “She said it was squatty.”

The other guy — his brother? his best friend? — doesn’t get it. “Squatty? What’s that mean? Is that a real word?”

For the first guy, the point is made. “Exactly! How the fuck should I know?” They look over a single giant mushroom, big as a volleyball, foraged in northern Wisconsin, on display like a circus animal. “Low to the ground, I guess. Low ceilings. Too low. Squat. Whatever.”

This earns him a little hmph from the other guy. “Squatty in Downers Grove,” says that guy. “I never thought I’d hear that.”

That night, three guys are drinking at Mei’s Kitchen, an indistinct hotel bar and restaurant on 11th Street, a block from Grant Park. They are just out of a trade show, alternately drinking expensive vodka and cloudy craft beers. Three guys — one in an American flag tie, the second in a knockoff Members Only jacket, the third scarfing a plate of chicken wings.

Flag Tie:I had two people approach me today about their meatpacking operation and moisture.

Members Only:That’s a big deal. Moisture.

Wings:I learned that at the operation in Pilsen. That was a matter of one drop of water.

Members Only:One drop. Right. In Pilsen.

Flag Tie:No, that was a vaccine operation. That wasn’t Pilsen.

Members Only:Sure it was.

Flag Tie:That was K.C., remember? Botulism.

Members Only:There’s a vaccine for botulism? In Kansas City? I don’t think so.

Flag Tie:That was the risk. Botulism. One drop of water.

Members Only:K.C.?

Flag Tie:Today was a meatpacking operation. They wanted the redundant sensors all over the fucking place. Big, big order. Big ask. What’s wrong?

Members Only:You OK?

Wings:I just swallowed a chicken bone. The whole thing.

Flag Tie:Not good.

Wings:I thought I was going to choke. I was going to say something. But I just kept, you know … I just swallowed.

Flag Tie:Man, slow down.

Wings:It’s gone. Wow. Anyway, in my world, everyone’s building sprinklers.

Flag Tie:There’s no room for error.

Members Only:You fucking have to slow down, Andre.

The substance and pace of exchanges vary by generation. College kids speak exclusively to one another. They interrupt habitually, punctuate exchanges with hoots and snorts and sighs. They talk like they text. These sounds are their emoji.

In the Art of Pizza on State Street, I come upon three such students — two black men and a white woman — huddling at 4 in the afternoon, pooling their money for some slices. They speak over one another, each of them reliably stepping on the last words spoken, their lines never arriving at any discernible point of termination.

“You’ll be in Texas before you eat again, so won’t you be … ,” says one.

“Oh no,” says another, counting change. “No. Damn! Shit, no. I gotta eat before that. I needs my dinner too, I’m …”

“Wait, here’s a dollar too.”

“Two? So don’t get two? Or get two, which …”

“Fuck yes, get two. We trying to get to three.”

“I meant, I got another dollar. Holla.”

“When you leave?”

“Three is better.”

“You mean my flight?”

“That’s $8. No, man. No. We can’t get three for $8. Yes, your flight. Yes, but …”

They look up at the posted prices, then into the eyes of the man at the counter.

“Shit.”

“Nah, man.”

“We won’t even get two slices, then.”

“Not enough.”

“Too damned much.”

“Just cheese, then.”

“Get the old ones. Pizza has a lifespan. Ask for the special.”

“Heard that.”

“Special? Damn, Roof. Look at him. He hates us.”

“He does not. Nah.”

“You hate us, don’t you?”

“Man, stop.”

“Shut up. He just wants to get paid.”

“Wait, wait, wait. Let me check this one thing.”

“I told you about that. Seriously. Unless you have a $5 bill right now, you’d better not be telling me to wait again. I’m hongray.”

“Let me check something.”

“I knew you had money on that card! I told you she had money.”

“Damn, now you’re going to check your card?”

“No, I’m checking my flight.”

“Fucking Texas, man.”

“Just get one slice.”

It wore on me. Eventually I came to ask myself: Where does it end? How do you go back to not paying attention to everything not meant for you? It’s one thing when eavesdropping is a happy accident, a momentary distraction. Hours of it, days of it, was leading me to lean in too far.

On the third day, I’m sitting in the Sky Ride Tap on Van Buren. I’ve come in hopes of overhearing some off-duty officers from the Metropolitan Correctional Center around the corner. Next to me sits a guy wearing a Blackhawks jacket and a hat advertising an HVAC outfit in Schaumburg. He’s making time with a woman reasonably named Tammy.

They have been drinking for an hour. And I’ve listened mercilessly, staring at the Weather Channel, drifting in and out of their exchange. It’s a snooze. They use too many names, refer too often to a cast of characters from Hyde Park, where they grew up. I can’t create a context for them.

Then Tammy’s voice gets more insistent and she starts speaking like a Gatling gun. I tune in without turning my head. She’s griping about a man she used to live with. She’d come to the end of her rope with him.

Tammy:The basic message I gave him was, I cannot attend to your, you know, your …

Blackhawks:I know. I get it.

Tammy:… activities.

Blackhawks:Oh wow. Yeah. I mean, yeah.

Tammy:I mean …

Blackhawks:Yeah. I know.

Tammy:I know you know. I already said.

Blackhawks:I meant I know how it is.

Tammy:Right?

She is so lit up. Her tone demands she be heard, as does her apparent amazement at what she’s lived through. Now I have to listen. I have to figure this out.

Tammy:I told him. I said, I just cannot attend to your …

Blackhawks:Right, right.

Tammy:… to your junk, you know.

Blackhawks:Yeah.

At this juncture, I make a serious mistake in the posture and position of my eavesdropping. When she says “junk,” I understand exactly what she means. And since she’s being so animated, I turn and take a little peek at her, over the shoulder of the Blackhawks guy. She’s kind of a hard-ass. But pretty. She doesn’t seem to notice. I look away.

Tammy:Not until you … you know.

Blackhawks:Right.

Tammy:Whatever. I’m not a nurse.

Blackhawks:I know.

Tammy:Not until you go to CVS, you absolute piece of shit!

I am compelled to take another look. And this time, she catches my eye. She squints. Then, without warning, she speaks directly to me.

Tammy:Hey, what are you looking at?

Me:Sorry.

Tammy:We’re talking about his penis. Peee-nisss. OK? Did you get that part?

I hold up a hand in a you-got-me gesture of surrender. Then she starts spinning her left hand, palm out, in front of her. Circular motion, rapid, a little chaotic, like what you see in the porthole window of a dryer. She is indicating the man’s crotch, that whole zone.

The Blackhawks guy looks at me. The bartender does too. I believe I muttered “sorry” one more time.

Tammy:It’s just … just so …

She cannot find the words. She is angry and hurt. I look down at my phone. I feel responsible. I shattered the moment by listening in. I stop with the notes, right then and there.

I never heard the end of her story. I can’t even tell you if she finished that sentence. I quit listening. I gave in to a dim thread of music. I drank my beer. Tammy and the Blackhawks guy stayed awhile longer. And when they left, I tried not to care where they were going.