Near the ground floor she leapt four steps to the concrete. Her legs went out from underneath her and she slammed into the rough wall. Wincing at the pain, the teenager climbed to her feet, hearing his footsteps, seeing his shadow on the walls.

Geneva looked at the fire door. She gasped at the chain wrapped around the bar.

No, no, no…The chain was illegal, sure. But that didn’t mean the people who ran the museum wouldn’t use one to keep thieves out. Or maybe this man had wrapped it around the bar himself, thinking she might escape this way. Here she was, trapped in a dim concrete pit. But did it actually seal the door?

Only one way to find out. Go, girl!

Geneva pushed off and crashed into the bar.

The door swung open.

Oh, thank -

Suddenly a huge noise filled her ears, pain searing her soul. She screamed. Had she been shot in the head? But she realized it was the door alarm, wailing as shrilly as Keesh’s infant cousins. Then she was in the alley, slamming the door behind her, looking for the best way to go, right, left…

Get her down, cut her, cut the bitch…

She opted for right and staggered into Fifty-fifth Street, slipping into a crowd of people on their way to work, drawing glances of concern from some, wariness from others. Most ignored the girl with the troubled face. Then, from behind her, she heard the howl of the fire alarm grow louder as her attacker shoved the door open. Would he flee, or come after her?

Geneva ran up the street toward Keesh, who stood on the curb, holding a Greek deli coffee carton and trying to light a cigarette in the wind. Her mocha-skinned classmate – with precise purple makeup and a cascade of blonde extensions – was the same age as Geneva, but a head taller and round and taut as a drum, round where she ought to be, with her big boobs and ghetto hips, and then some. The girl had waited on the street, not having any interest in a museum – or any building, for that matter, with a no-smoking policy.

“Gen!” Her friend tossed the coffee cup into the street and ran forward. “S’up, girl? You all buggin’.”

“This man…” Geneva gasped, felt the nausea churn through her. “This guy inside, he attacked me.”

“Shit, no!” Lakeesha looked around. “Where he at?”

“I don’t know. He was behind me.”

“Chill, girl. You gonna be okay. Let’s get outa here. Come on, run!” The big girl – who cut every other P.E. class and had smoked for two years – started to jog as best she could, gasping, arms bouncing at her sides.

But they got only half a block away before Geneva slowed. Then she stopped. “Hold up, girl.”

“Whatchu doing, Gen?”

The panic was gone. It’d been replaced by another feeling.

“Come on, girl,” Keesh said, breathless. “Move yo’ ass.”

Geneva Settle, though, had made up her mind. Anger was what had taken the place of her fear. She thought: He’s goddamn not getting away with it. She turned around, glanced up and down the street. Finally she saw what she was looking for, near the mouth of the alley she’d just escaped from. She started back in that direction.

A block away from the African-American museum Thompson Boyd stopped trotting through the crowd of rush-hour commuters. Thompson was a medium man. In every sense. Medium-shade brown hair, medium weight, medium height, mediumly handsome, mediumly strong. (In prison he’d been known as “Average Joe.”) People tended to see right through him.

But a man running through Midtown draws attention unless he’s heading for a bus, cab or train station. And so he slowed to a casual pace. Soon, he was lost in the crowd, nobody paying him any mind.

While the light at Sixth Avenue and Fifty-third remained red, he debated. Thompson made his decision. He slipped off his raincoat and slung it over his arm, making sure, though, that his weapons were accessible. He turned around and started back toward the museum.

Thompson Boyd was a craftsman who did everything by the book, and it might seem that what he was doing now – returning to the scene of an attack that had just gone bad – was not a wise idea, since undoubtedly the police would be there soon.

But he’d learned that it was times like this, with cops everywhere, that people were lulled into carelessness. You could often get much closer to them than you otherwise might. The medium man now strolled casually through the crowds in the direction of the museum, just another commuter, an Average Joe on his way to work.

It’s nothing less than a miracle.

Somewhere in the brain or the body a stimulus, either mental or physical, occurs – I want to pick up the glass, I have to drop the pan that’s burning my fingers. The stimulus creates a nerve impulse, flowing along the membranes of neurons throughout the body. The impulse isn’t, as most people think, electricity itself; it’s a wave created when the surface of the neurons shifts briefly from a positive charge to a negative. The strength of this impulse never varies – it either exists or it doesn’t – and it’s fast, 250 m.p.h.

This impulse arrives at its destination – muscles, glands and organs, which then respond, keeping our hearts beating, our lungs pumping, our bodies dancing, our hands planting flowers and writing love letters and piloting spacecraft.

A miracle.

Unless something goes wrong. Unless you’re, say, the head of a crime scene unit, searching a murder scene in a subway construction site, and a beam tumbles onto your neck and shatters it at the fourth cervical vertebra – four bones down from the base of the skull. As happened to Lincoln Rhyme some years ago.

When something like that occurs, then all bets are off.

Even if the blow doesn’t sever the spinal cord outright, blood floods the area and pressure builds and crushes or starves the neurons. Compounding the destruction, as the neurons die they release – for some unknown reason – a toxic amino acid, which kills even more. Ultimately, if the patient survives, scar tissue fills the space around the nerves like dirt in a grave – an appropriate metaphor because, unlike neurons in the rest of the body, those in the brain and spinal cord do not regenerate. Once dead, they’re numb forever.

After such a “catastrophic incident,” as the men and women of medicine so delicately put it, some patients – the lucky ones – find that the neurons controlling vital organs like lungs and heart continue to function, and they survive.

Or maybe they’re the unlucky ones.

Because some would rather their heart stopped cold early on, saving them from the infections and bedsores and contractures and spasms. Saving them too from attacks of autonomic dysreflexia, which can lead to a stroke. Saving them from the eerie, wandering phantom pain, which feels just the same as the genuine article but whose searing aches can’t be numbed by aspirin or morphine.

Not to mention an utterly changed life: the physical therapists and the aides and the ventilator and the catheters and the adult diapers, the dependency…and the depression, of course.

Some people in these circumstances just give up and seek out death. Suicide is always an option, though not an easy one. (Try killing yourself if all you can move is your head.)

But others fight back.

“Had enough?” the slim young man in slacks, white shirt and a burgundy floral tie asked Rhyme.

“No,” responded his boss in a voice breathless from the exercise. “I want to keep going.” Rhyme was strapped atop a complicated stationary bicycle, in one of the spare bedrooms on the second floor of his Central Park West town house.

“I think you’ve done enough,” Thom, his aide, said. “It’s been over an hour. Your heart rate’s pretty high.”

“This is like bicycling up the Matterhorn,” Rhyme gasped. “I’m Lance Armstrong.”

“The Matterhorn ’s not part of the Tour de France. It’s a mountain. You can climb it, but you can’t bike it.”