SHE CLICKS off something in her mind and flicks on a different switch. She will be clinical. She will be a detective, not a sister. She will view a crime scene, not her dead twin brother. Clutching, clinging with all her might to her father’s arm, stepping onto the tiled entryway of the condo.

She knows the place. It opens into a great room, a small kitchen to the left, bedroom and bathroom in the back. Pretty standard high-rise condo in Chicago, anyway, but she knows this one in particular. She’s been here before.

The first time was yesterday.

The apartment goes immediately silent, as if someone raised a hand for quiet. Everyone busy at work dusting or photographing or collecting samples or talking—everyone stops as the chief of Ds and his daughter, a detective in her own right, enter the room.

Patti does her detective thing. No sign of struggle in the front room, the main room. Furniture in place, the tile shiny and clean, no sign of activity other than what the detectives and technicians are doing.

Someone had turned the air conditioner on full blast, the air good and cool, which should moderate lividity—

Lividity. My brother’s dead body.

“It’s in the bedroom,” says Wizniewski, leading the way. “Now, I can’t let you go in there, Chief, you understand that. You’re the immediate family of one of the—”

“I just want to see. I won’t walk in, Lieutenant.” Her father, in that precise, resolute way he has of speaking, though she is probably the only one who recognizes the tremor in his voice.

Patti’s eyes moving about, seeing nothing. Amy kept a clean apartment. She’s seen, in her time, plenty of attempts to clean up a crime scene, and this shows no signs of recent scrubbing or spraying or incomplete attempts to wipe away smears or vacuum up debris. No violence happened in the great room or the kitchen.

Everything that happened happened inside the bedroom.

Red crime-scene tape, the inner perimeter, blocking access to the bedroom.

Her father delicately positions himself ahead of Patti, a protective gesture, allowing him the first look inside the bedroom. He leans over the red tape, takes a deep breath, and turns to his right to look inside.

He immediately squeezes his eyes shut and turns away, holding his breath, immobile. He swallows hard, opens his eyes—now deadened, filled with horror—and turns back and looks again.

He murmurs, “What in God’s name happened here?”

She hears Wizniewski breathe a heavy sigh. “The position of the bodies, everything—it looks pretty much like what it looks like, sir.”

Patti steels herself and angles past her father, looking into the room.

Three dead bodies. Kate—Detective Katherine Fenton—lying dead on the carpet, her eyes staring vacantly at the ceiling, a single gunshot wound over her right eye. A pretty clean shot, only a trickle of blood running from the wound, the rest of the blood following gravity’s pull, probably leaving through the exit wound in the back of her skull, soaking the carpet beneath her, obscured by her auburn hair. Her Glock pistol lying just outside the reach of her left hand.

She focuses on Kate—not because she’s never seen a dead body (she’s seen dozens), and not because she liked Kate (she didn’t), but because it’s preferable to what else there is to see in the room, something that thus far has only leaked into her peripheral vision.

Two bodies on the bed—her brother Billy and Amy Lentini, each of them naked. Amy with a GSW to the heart, a single shot. Her body sprawled out, her head almost falling off the bed’s left side, a large bloodstain barely visible behind Amy, where she bled out.

And then—

Billy. She fixes on him, her heart drumming furiously, heat spreading across her body as she looks at her twin brother sitting upright on the bed, blood streaked down the right side of his face, his head lolled to the side, his eyes closed and peaceful.

Take away the blood, the wound, and he could just as easily be sleeping. He could do that in a way she never could. She’s always had to sleep on her side, a pillow between her legs. Not Billy. He could sleep all night in a chair or sitting up in bed. He could catch some shut-eye in the middle of geometry class without making a single sound, without snoring or jerking or anything that would give him away—he could sleep in secret just as he could live in secret, just as he could do just about anything in secret. He could hide his fears, his emotions, his thoughts, his sorrows behind that implacable, genial expression of his. She was the only one who knew that about him. She was the only one who understood him.

You’re just sleeping, Billy.

Please. It’s me, Billy, c’mon. Pop open those eyes and say, “Surprise!”

Please be sleeping.

“Too early to know, of course,” Wizniewski says to her father. “Sure looks like Detective Fenton walked in—on this, on them—and opened fire. Billy shot back. They killed each other. A fuckin’ shoot-out at the OK Corral right here in the bedroom.”

“Ah, Jesus.”

No, Patti thinks to herself. That’s not what happened here.

Her legs giving out, her head dizzy. An arm pulling her away, her father, and just as much as she dreaded seeing Billy, even more so now she dreads taking her eyes off him.

Her father pulls Patti back into the main room. The officers all stop what they’re doing and stare at father and daughter as if they were museum exhibits.

Behind Patti, medical personnel slip past and head into the bedroom with body bags.

Body bags. She can’t stomach the thought.

“We do this by the book,” her father says to the room. “That’s my son in there, yes, but he was a cop. Before anything else, he was a cop. A damn fine one. Honor him and Detective Fenton by doing this case right. By the book, people. No mistakes. No shortcuts. Be at your best. And get me—”

Her father chokes up. Solemn nods all around. Patti’s chest is burning, so hot she struggles to breathe.

“Get me a solve,” her father finishes. “Solve this crime.”

Suddenly feeling claustrophobic, Patti turns and heads for the door. This isn’t real, she decides. This didn’t happen.

“Oh, my God.”

Just as she’s at the door, she hears the words. Not from her father. Not from any of the officers in the main room.

From the medical personnel in the bedroom.

“We have a pulse! We have a pulse!” the man shouts. “This one’s still alive!”

DETECTIVE BILLY Harney rubbed his hands, his breath lingering, frozen, in front of him, a wispy reminder of how cold Chicago can be in the middle of March. Three hours was long enough inside the SUV. He hated stakeouts. Even though this one was his idea. His case.

It started with a dead undergrad, a junior at U of C. The area around the campus—Hyde Park—had some rough spots, and everyone chalked up the murder to urban violence. But they didn’t know what Billy knew from a download of the data on her cell phone—that this young woman made money in her spare time as an escort. She worked through an Internet site that was taken down the day after her death, but her text messages indicated that she had one particular client who had some unusual needs and was willing to pay top dollar for them.

In a nutshell, he liked to choke her during sex.

He was a trader, married with kids, who made more money in a week than Billy made in two years. The kind of guy who could buy an army of top-shelf lawyers to defend him. Billy wanted this asshole to drop his guard, to relax, so he leaked some news that a suspect was in custody for the undergrad’s murder, that it looked like another garden-variety attack in Hyde Park. And then Billy followed the scumbag trader.

Precisely one week ago, at 9:00 p.m., the trader entered the brownstone down the street. Billy got him on video but wasn’t sure what was happening inside, so he laid low. A little recon work told him that this place was a high-rent brothel.

So assuming that this guy had a regular appointment—and Billy was willing to lay down good money that he did—tonight should be the night. Catch him with his pants down and offer a simple trade: no arrest for the prostitution if you answer a few questions about a dead undergrad. Billy could take it from there. Always better to start a Q and A with the subject sweating his ass off and eager to please.

He pushed back the sleeve of his overcoat and checked his watch. Half past eight. He blew warm air into his hands.

“Sosh, how we doin’?” he said into his radio to Soscia, the cop in one of the other vehicles, two blocks down, staking out the brownstone from the east.

The response came through Billy’s wireless earbud. “Ready, willing, and able,” Sosh said. “Just like your sister.”

“My sister wouldn’t touch you with a six-foot pole. And neither would Stanislowski.”

“Who the fuck is Stanislowski?”

“A six-foot Pole.”

“Harney, get back in the car.” This from his partner, Katherine Fenton, sitting in the warm car just next to him.

“Sosh, how’s your rook holding up?” Soscia had a new detective working with him, a nice kid named Reynolds. “You know I bought him lunch today.”

“Yeah, I fuckin’ know. He said putting extra pinto beans on the burrito was your idea. And I’ve been stuck in this truck with him for three hours.”

Billy smirked. Stakeouts weren’t all bad. “Hey, Crowley, you still awake?”

The third car, Crowley and Benson.

“Yeah, just dyin’ from all this excitement. How many cops does it take to rope one lowlife?”

Sosh and Crowley had both raised that point. But this was the hoity-toity part of town, the Gold Coast, and he didn’t need any mistakes. He wanted old hands like Sosh and Crowley on this.

“What, Crowley, you got somewhere better to be? I know your old lady isn’t home, ’cause she’s in the car with Sosh right now.”

“Well, then, Sosh won’t be getting no action, neither.”

It was freakin’ cold out here. Ten minutes out of the car and he felt the sting in his toes. “Hey, Fenton,” he said to his partner. “What do you call a clairvoyant midget who escapes police custody?”

He opened the passenger door and climbed into the warm SUV. Detective Fenton—Kate—shot him a sidelong glance.

“A small medium at large,” said Billy.

Sosh liked that one. Kate not so much.

“Hey.” Billy stiffened in his seat. “Two o’clock. Our first action.”

“Right.” Kate talked into her radio. “White male traveling northbound on Astor in a brown coat, brown cap.”

Katie, Billy thought to himself, always so intense, so keyed up. He’s the only person out here walking; they can probably spot him.

But he let it go. Telling Kate to calm down was like throwing a match on a pool of gasoline. “You got him, Crowley?”

“Aw, yeah. He’s smilin’ nice and pretty for the camera.”

“I know that guy,” said Fenton. “Right? That’s that guy from that show.”

“What show—”

“That show—that movie-critic thing…Front Row or something.”

“Right.” He’d seen it. The Front Row with…couldn’t place the name. “We should arrest him for that alone.”

“Yeah, it is—that’s him,” said Sosh. “Brady Wilson.”

They sat tight as the film critic waltzed up the steps of the brownstone. Before he pressed the buzzer, a man in a dark suit opened the door and ushered him in.

“Fancy,” said Crowley. “Do we think he’s here for business?”

“Definitely,” said Billy. “One guy owns all three floors. He claims to live there, but I haven’t seen any signs of anyone living there since I started sitting on it. Three floors, probably eight or ten bedrooms.”

“So this could be a real party we got going on.”

“Maybe we should call in Vice,” said Billy, knowing the reaction he’d receive.

“Fuck Vice,” said Katie. “This is ours.”

“Jesus Christ,” said Sosh. “Jesus H. Christ on a popsicle stick.”

“Talk to me, Sosh.”

“You’re never gonna believe who just walked past me. Crowley, you guys got video on this?”

“Roger that, we’ve got—holy mother of God.”

“Will you guys tell me already?”

Billy wished he had a high-powered scope. He wasn’t expecting this. He fished binoculars from the backseat and trained them on the steps of the brownstone as an elderly man trudged up toward the front door.

“Well, well, well,” said Billy. “If it isn’t His Excellency the Most Reverend Archbishop Michael Xavier Phelan.”

“Lord, he is not worthy; Lord, he is not worthy.”

Billy couldn’t decide if he was excited or disappointed. His partner, Kate, had made up her mind—she was all in. This had just become a heater case.

“Everyone take a breath,” said Billy. “He’s probably just going in to hear confession.”

A black SUV, not very different from the one Billy was in at the moment, pulled up at the curb outside the brownstone. The windows were tinted, as best as Billy could tell through binoculars in poor light. That was odd, because tinted windows were a no-no in this state, with only limited exceptions.

Exceptions such as vehicles that transport government officials.

Billy moved his binoculars down to the license plate, then back up.

“Oh, shit,” he said. “I better call the Wiz.”

“Why?” Kate asked, almost bouncing out of her seat.

Billy shook his head.

He said, “Because the mayor of Chicago just got out of that car.”

BILLY CLIMBED into the sedan a block away from his stakeout point. The car reeked of cigar smoke. Wizniewski carried that odor on him at all times.

The Wiz turned his round face toward Billy. “How many inside?”

“We’ve seen twelve people go in,” said Billy. “No two of them at the same time. Like it’s all synchronized, so nobody sees anyone else. As discreet as discreet gets. Seven of them we can’t ID. One of them is my suspect in the undergrad’s murder, the trader. One of them is this film critic who has a TV show, Brady Wilson. Another is a male black who Sosh’s partner says is some rapper named Chocolate Q.”

“The fuck does that stand for?”

Billy looked at the Wiz. “When I arrest him, I’ll ask him.”

Wizniewski rubbed his eyes. “And you’re sure about the archbishop?”

“Positive.”

“And the…” Wiz’s lips came together to make an m sound, but he couldn’t bring himself to say the word.

“It’s the mayor. No question. His security detail dropped him off but didn’t go inside. The car is parked down the block. How we doin’ on numbers?”

“I have ten uniforms ready to assist on my call,” said the Wiz.

Ten plus the six detectives should be enough.

“You don’t have to do this,” said Wizniewski. “You know that.”

He meant that Billy didn’t have to arrest everybody. He could do what he came there to do—arrest the suspect in the undergrad’s murder and avert his eyes to anything else.

You chickenshit. The Wiz was always thinking of tomorrow, always looking to climb the ladder, always playing office politics. This thing could fall either way, Billy realized. The police superintendent, after all, was appointed by the mayor. The supe might not be too happy about the mayor getting bagged; if the mayor went down, he might, too. Billy could get a gold star on his report card for this or he could see the effective end of his advancement in the department. And the Wiz could, too. This could be the best thing that ever happened to their careers or it could be the worst thing. A guy like the Wiz, always weighing the political consequences, avoided risks like this.

But Billy wasn’t wired the same way as the Wiz. He kept it simple. It came down to three words for him—Do your job. Any consideration beyond that made you lose your edge. It blurred your focus and made you less than the cop you were supposed to be.

Do your job. He had probable cause to believe a crime was in progress, and that was all that mattered.

“Are you calling me off?” Billy asked.

“No, no.” The Wiz drew a line in the air. “Absolutely not.”

Absolutely not, because that would be even worse for the Wiz, telling a detective not to investigate a crime because it involved a high-ranking public official. That could mean dismissal from the force, maybe even criminal charges. The Wiz was far too cautious a politician to ever let something like that go on his record.

“Everything you do from this moment on will be carefully scrutinized,” said the Wiz. “Reporters, BIA, the IG, defense lawyers—everyone’s gonna put you under a magnifying glass. You get that, right? I’m just saying it’s okay with me if you don’t wanna push this. If you wanna stick with the murder suspect and leave everything else alone. We’re not Vice cops. We don’t make a habit of arresting johns and hookers.”

Billy didn’t respond, just waited him out.