“I’m okay,” he said. Sounding nothing but adolescent.

She smiled in his general direction but he was looking away again. Without another word, she shoved at the door and hurried out to the parking lot.

The night was warm and sweaty. Two detectives she didn’t recognize slouched toward the far end, laughing, chatting. One pivoted to look at her, then returned his attention to his partner’s banter.

She hurried to her car, putting Isaac’s discomfiture out of her mind.

Time to focus: me, me me. Mongolian hot pot, they treat me well, I deserve to be treated well.

Maybe she’d pick up a magazine and read while she ate. Something not too challenging.

Playing with her chopsticks. Pretending to be content.

Then she’d go get Eric.

Stupid!

Isaac hunched at his desk, faced a grubby wall. Hot and sandy-eyed and abashed, alone in the detectives’ room except for that old guy, Barney Fleischer, who always seemed to be around but never seemed to be really working.

Fleischer had a radio on at low volume, some sort of easy-listening instrumental, didn’t even look up when Isaac entered. By now, no one in the detectives’ room noticed his comings and goings. He was a fixture to all of them.

Including Petra.

Asking her to dinner when she’s rushing out on a case! What had he been thinking?

Unlike Fleischer, Petra worked. The job mattered to her. Despite all the frustration, chasing down leads that failed to materialize.

A woman like that needed to parcel out her time carefully. Why in the world would she even contemplate stopping for dinner?

With him.

To her, he was an assignment, nothing more.

And yet, she’d been generous with her time. Letting him ride along, sharing details of cases.

That skin, those eyes. The way her black hair just floated into place.

Stop it, stupid.

He started to wonder again about the June 28 murders. Was his hypothesis all part of an inane infatuation?

He’d been so certain. The thrill of discovery when he first came across the pattern had nearly blown him out of his seat.

Eureka!

Ha.

At the time, he thought he’d been careful not to leap into conjecture without calculating and recalculating, subjecting his hypotheses to multiple tests of significance. The data had seemed clear. This was something.

But what if he’d convinced himself a mathematical quirk was meaningful because he’d been blinded by his own bullshit?

Because he’d wanted to produce for Petra.

Did it all boil down to preening, the ludicrous mating rituals of an absurd little game bird?

God, he hoped not.

No, it had to be real. Petra was an expert and she believed it.

Because he’d worn her down?

All his life- his academic life- he’d been told he was built for success. That the combination of brains and perseverance couldn’t miss.

But perseverance could be pathological, couldn’t it?

He had that in him: the blindered compulsiveness, the irrational relentlessness.

Barney Fleischer looked over his shoulder and stared and said, “Hey, there.”

“Hey, Detective Fleischer.”

“Burning the midnight oil?”

“A few hours left till then.”

“She’s out, you know. Left a few minutes ago.”

“I know,” said Isaac.

Fleischer studied him and Isaac could see cold, hard appraisal in the old guy’s eyes. Once a detective…

“Anything I can do for you, son?”

“No, thanks,” said Isaac. “I thought I’d do some paperwork. On my research.”

“Oh,” said Fleischer. He turned his music up louder, resumed whatever he’d been doing.

Isaac took out his laptop, booted up, called up a page of numbers, pretended to be concentrating. Instead, he flashed back to the agony of self-doubt.

Step back, be objective.

Six victims, nothing in common but the date. His calculations said it had to be meaningful, but could he be trusted to think straight?

No, no, however dorky his motives, this was real. He’d run the numbers too many times for it to be anything but real.

June 28. Today was the eighteenth.

If he was right, someone, some unsuspecting, innocent, random person would step out into a night full of expectations only to experience the crushing pain of a cranium pulverized to pulp.

Then nothing.

Suddenly, he wanted to be wrong. That had never happened before.

WEDNESDAY, JUNE 19, 1:20 A.M., TERMINAL 4, LAX

The flight’s arrival had been delayed for two hours and the baggage claim area stank of uncertainty.

All those weary loved ones sitting, pacing, peering at the board, shaking their heads, sometimes cursing, as the numbers got worse.

Petra spent the time sitting and rereading a copy of People magazine.

The bath she’d taken three hours ago had been okay, but she’d been too hyped up to enjoy it.

Jumping out, toweling off, spending a lot of time on her makeup and clothes, finally selecting a tight black top over gray linen slacks. The smooth, black Wonderbra gave her a lift nature hadn’t.

She drove quickly to the airport, found parking after two go-rounds and still arrived early.

Then she waited.

When the arrival time was finally announced- an hour away- she left the terminal to take a walk along the dim, mostly deserted walkways of the airport’s lower level.

A woman walking alone. Her gun was in her purse. No metal detectors anywhere near the baggage claim. A clear lapse of security that she welcomed tonight.

When she got back, passengers from a Mexico City flight had clogged the area. When they finally cleared, the “Landed” sign was flashing for Eric’s flight and she stationed herself near the swinging doors that bottomed the arrival ramp, and peered through the glass.

Sparse flight, just a trickle of zombies bumping down the ramp. Eric was among the last passengers to appear and she spotted him well before he got to the doors.

Dark blue sweatshirt, faded jeans, sneakers, his little olive-green, Swiss mountain-climber’s backpack slung over one shoulder.

Light wood cane in his left hand.

A limp.

When he saw her he straightened and waved the cane as if it were superfluous.

He came through the doors, she rushed him, hugged him, felt bones and sinew and tension. The cane bumped against her leg.

“Excuse me!” Annoyed female voice.

They were blocking the exit. Stepping aside, Petra caught a murderous glance from an all-in-black harridan who tried to engage her in extended ocular warfare. She smiled and hugged Eric again.

He said, “One suitcase.” They walked toward the carousel. Petra reached for his backpack.

He held on to it. “I’m fine.” Handing her the cane, to prove it.

They stood there, silent, as bags bumped through the chute.

Boy, this is romantic.

She got between him and the revolving luggage, kissed him hard.

On the ride home, he said, “Thanks for picking me up.”

“It was a tough decision.”

He touched her knee, withdrew.

“It’s good to see you,” she said.

“Good to see you.”

“How’s your leg? Really.”

“It’s okay. Really.”

“How long do you have to use that thing?”

“I could probably ditch it now.”

She took Century to the 405 North. Not much traffic on the freeway. Good time to challenge the speed limits.

“Your place?” she said. Thinking she really didn’t want to drive to Studio City.

“We could go to your place.”

“We could.”

When they arrived, he pronounced himself “rancid,” and took a shower. She ran the water and as it warmed, fixed him coffee. When he slipped off his sweatshirt, she saw white flesh and bones, the thin sheath of muscle that rescued him from downright scrawny. A bandage on his shoulder.