Morning rush-hour traffic on the I-10 Expressway flowed as languidly as the Mississippi River that wound through New Orleans.

When Detective Carson O’Connor got off the expressway in the suburb of Metairie, intending to use surface streets to make better time, the morning took a turn for the worse.

Stopped interminably at an intersection, she impatiently kneaded the steering wheel of her plainwrap sedan. To dispel a growing sense of suffocation, she rolled down the window.

Already the morning streets were griddles. None of the airheads on the TV news, however, would try to cook an egg on the pavement. Even journalism school left them with enough brain cells to realize that on these streets you could flash-fry even ice cream.

Carson liked the heat but not the humidity Maybe one day she’d move somewhere nicer, hot but dry, like Arizona. Or Nevada. Or Hell.

Without advancing a foot, she watched the minute change on the dashboard clock display- then spotted the reason for the jam-up.

Two young hoods in gang colors lingered in the crosswalk to block traffic each time the light turned green. Three others worked the line, car to car, tapping on windows, extorting payoffs.

“Clean your windshield. Two bucks.”

Like a patter of semiautomatic gunfire, car doors locked one after another as the young entrepreneurs made their sales pitch, but no car could move forward until the driver paid the tariff.

The apparent leader appeared at Carson’s window, smug and full of false good humor. “Clean your windshield, lady.”

He held a filthy rag that looked as if it had been fished out of one of the city’s many weedy canals.

A thin white scar on one darkly tanned cheek was puckered at several suture points, suggesting that he’d gotten into a knife fight on a day when the ER physician had been Dr. Frankenstein. His wispy beard implied testosterone deficiency.

Getting a second, closer look at Carson, Scar-face grinned. “Hey, pretty lady. What you doin’ in these shabby wheels? You was made for Mercedes.” He lifted one of the wipers and let it slap back onto the windshield. “Hello, where’s your mind? Not that a long-legged fresh like you needs a mind.”

An unmarked sedan had advantages in low-profile detective work; however, back when she’d driven a black-and-white patrol car, Carson had never been bothered by crap like this.

“You’re breaking the law,” she told him.

“Somebody in a mood this mornin’.”

“The windshield’s clean. This is extortion.”

“I charge two bucks to clean it.”

“I advise you to step back from the car.”

The kid lifted his rag, prepared to smear the windshield. “Two bucks to clean it, three bucks not to clean it. Most ladies, whether they’re male or female ladies, take option two.”

Carson unbuckled her seatbelt. “I asked you to step back from the car.”

Instead of retreating, Scarface leaned into the window, inches from her. Breath sweetened by a morning joint, soured by gum disease. “Gimme three bucks, your phone number, a nice apology- and maybe I don’t mess with your fine face.”

Carson grabbed the gink’s left ear, twisted it hard enough to crack cartilage, and slammed his head sideways against the door post. His howl sounded less like that of a wolf than like that of an infant.

She let go of his ear and, exiting the sedan, opened the door into him with enough force to knock him off his feet.

As he sprawled backward, rapping his head on the pavement hard enough to summon constellations to an inner planetarium, she planted one foot on his crotch, grinding down just enough to make him squirm and to pin him in place for fear that she’d make paste of his jewels.

Shoving her police ID toward his face, she said, “My phone number is nine-one-one.”

Among the hostage cars, heads up and alert, Scarface’s four ace kools were looking at him, at her, stunned and angry but also amused. The guy under her foot was a homey, and a humiliation to one home boy was a humiliation to all, even if maybe he was a little bit of what they called hook homey, a phony.

To the nearest of Scarface’s friends, Carson said, “Stall it out, shithead, unless you want a hole in your doo-rag.”

The gink under her foot tried to crab-walk away, but she stepped down harder. Tears sprang to his eyes, and he chose submission over the prospect of three days with an ice pack between his legs.

In spite of her warning, two of the other four gangbangers began to edge toward her.

Almost with the nimbleness of prestidigitation, Carson put away her ID and produced the pistol from her holster.

“Check it out, this lady under my foot, he’s been scratched”-which meant embarrassed- “but none of you has. Nothin’ here for you but two years in stir, maybe lit up and crippled for life.”

They didn’t split, but they stopped moving closer.

Carson knew they were less concerned about her pistol than about the fact that she talked the talk. Since she knew the lingo, they assumed-correctly-that she had been in situations like this before, lots of them, and still looked prime, and wasn’t afraid.

Even the dumbest gangbanger-and few would win a dime on Wheel of Fortune-could read her credentials and calculate the odds.

“Best to break, best to book,” she said, advising them to leave. “You insist on bumping titties, you’re gonna lose.”

Ahead of her plainwrap sedan, closer to the intersection, cars began to move. Whether or not they could see what was happening in their rearview mirrors, the drivers sensed the shakedown had ended.

As the cars around them began to roll, the young entrepreneurs decided there was no point to lingering when their customer base had moved on. They whidded away like walleyed horses stampeded by the crack of thunder.

Under her foot, the windshield-washer couldn’t quite bring himself to admit defeat. “Hey, bitch, your badge, it said homicide. You can’t touch me! I ain’t killed nobody.”

“What a moron,” she said, holstering the pistol.

“You can’t call me a moron. I graduated high school.”

“You did not.”

“I almost did.”

Before the creep-predictably-took offense at her impolite characterization of his mental acuity and threatened to sue for insensitivity, Carson’s cell phone rang.

“Detective O’Connor,” she answered.

When she heard who was calling and why, she took her foot off the gangbanger.

“Beat it,” she told him. “Get your sorry ass out of the street.”

“You ain’t lockin’ me?”

“You’re not worth the paperwork.” She returned to her phone call.

Groaning, he got to his feet, one hand clutching the crotch of his low-rider pants as if he were a two-year-old overwhelmed by the need to pee.

He was one of those who didn’t learn from experience. Instead of hobbling away to find his friends, telling them a wild story about how he’d gotten the best of the cop bitch after all and had punched out her teeth, he stood there holding himself, ragging her about abusive treatment, as though his whining and threats would wring from her a sudden sweat of remorse.

As Carson concluded the call, pressed end, and pocketed the phone, the offended extortionist said, “Thing is, I know your name now, so I can find out where you live.”

“We’re obstructing traffic here,” she said.

“Come jack you up real good one night, break your legs, your arms, break every finger. You got gas in your kitchen? I’ll cook your face on a burner.”

“Sounds like fun. I’ll open a bottle of wine, make tapas. Only thing is, the face gets cooked on the burner-I’m lookin’ at it.”

Intimidation was his best tool, but she had a screwhead that it couldn’t turn.

“You like tapas?” she asked.

“Bitch, you’re crazy as a red-eyed rat on meth.”

“Probably,” she agreed.

He backed away from her.

With a wink, she said, “I can find out where you live.”

“You stay away from me.”

“You got gas in your kitchen?” she asked.

“I mean it, you psycho twat.”

?Ah, now you’re just draggin’ me,” Carson said, draggin’ meaning sweet-talking.

The gangbanger dared to turn his back on her and hobble away fast, dodging cars.

Feeling better about the morning, Carson got behind the wheel of the unmarked sedan, pulled her door shut, and drove off to pick up her partner, Michael Maddison.

They had been facing a day of routine investigation, but the phone call changed all that. A dead woman had been found in the City Park lagoon, and by the look of the body, she hadn’t accidentally drowned while taking a moonlight swim.