Pierre squinted, trying to watch but also trying to shield his eyes. Avi moved out of the stairwell entrance, and two of his men appeared behind him, also gulping for breath. One was holding his side and grimacing in agony. After a moment, Avi staggered to the south edge of the roof, as far from the noise of the helicopters as possible, and pulled out his cellular.

Pierre, meanwhile, picked up the crowbar and, using it as a short cane, keeping all weight off his destroyed left knee, hobbled over to the north edge, the pain almost unbearable, fighting nausea and dizziness with every step. When he got to the meter-high lip around the roof, he collapsed against it and brought both hands to his knee. He could hear the pounding of the helicopter blades, out of sight below him, next to the building.

“This is the police,” said a female voice from a bullhorn on the second copter; the voice was all but lost in the noise from the dueling rotors. “You are ordered to land.”

Pierre forced himself to his feet, using the lip to support himself. He almost blacked out from the pain; his body shook with agony and chorea.

Looking down was dizzying: forty stories of sheer glass, leading straight to the asphalt parking lot. Five SFPD squad cars were pulling up outside the building, sirens blaring. A few meters to Pierre’s right, and about ten meters below, was the silver copter with Marchenko and Sousa in it.

Marchenko could probably see directly into Craig Bullen’s office, with its redwood paneling and priceless paintings.

The cockpit was only a short distance away from the side of the tower.

The SFPD copter had moved alongside it now, as if trying to get a bead for a shoot-out. Pierre could clearly see the female pilot and her male companion, both uniformed, in the bubblelike cockpit. They seemed to be arguing with each other, and then the police copter started moving away, whichever one of them who felt flying this close to the building was dangerous having won the fight.

The rotor on Sousa’s copter was a circular blur below Pierre. The noise was deafening, but it would be only a matter of seconds before Sousa would head away from the building. He could make a beeline out into the Pacific, out over international waters, beyond the SFPD’s — or even the DOJ’s — jurisdiction, perhaps landing on a boat and sailing down to Mexico or beyond; surely there was more to Marchenko’s escape plan than just the helicopter.

Pierre hefted the crowbar, gauging its weight. It probably wouldn’t work — probably would just be deflected away. But he wasn’t about to stand by and do nothing —$

Pierre closed his eyes, summoning all the control and all the strength he had left. And then he threw the crowbar as hard as he could, spinning it vertically end over end, down into the helicopter’s twirling blades, aiming for the outer edge of the rotor disk.

He was prepared to stagger back, in case the crowbar was sent flying up toward him.

It hit with a horrible clanging sound. The helicopter began vibrating, tipping toward the building, and—$

— the blades touched glass, sending a shower of sparkling shards down toward the ground below—$

— and then the blades began slicing through the metal frame of the curtain wall between two windows, dicing the metal into small fragments, sparks flying everywhere as each successive pass brought the blades into contact at a slightly different angle.

The copter was traveling forward now, and the rotor disk hit the wall between adjacent offices, the tips of the blades splintering the redwood paneling with a buzz-saw sound, then digging into the concrete firewall behind. The tips of the rotor were immediately ground off, and more and more of them sheared away with each revolution, the blades shortening, metal bits flying like confetti.

Then the jagged edge of the rotor dug into the concrete, sending powdery chunks of it airborne until, with a shriek of tortured metal, the rotor came to a dead halt.

The copter tipped forward again, the bird itself now rotating slowly clockwise, its tail rotor swinging into the side of the building, more windows shattering and office furniture splintering.

The copter’s turbines were screaming; smoke poured from the engine compartment and flames shot from the exhausts. The cockpit tipped forward, and the whole vehicle began to drop, story after story after story.

Pierre could see people far below scattering, trying to get out of its way.

Pierre heard footfalls, all but drowned out by the thunder of the police copter. Avi was running across the rooftop.

Sousa’s chopper continued to fall, almost as if in slow motion, its foreshortened blades now revolving lamely, providing a small amount of lift. It passed floor after floor, diminishing in apparent size, until—$

Hitting the pavement like an egg, metal and glass splashing everywhere —$

— and then, like a flower opening, flames expanding outward from the crash as the copter’s fuel exploded. Soon a pillar of black smoke rose up to the fortieth floor and beyond.

The SFPD copter circled around, surveying the scene, then descended for a landing in the far parking lot.

Pierre looked down at the inferno below, ringed by spectators, illuminated by low, red sunlight and roaring flames reflecting off the windows, and by revolving lights on the police cars. At long, long last, Ivan Grozny was dead.

Pierre staggered back a step, turned around, and collapsed in agony against the short wall around the roof’s edge.

“Are you okay?” asked Avi, leaning in to look at him after seeing his fill of the carnage below.

Pierre’s hands were on his shattered knee again. The pain was incredible, like daggers being jackhammered into his leg. Wincing, he shook his head.

Avi flipped open his cellular phone. “Meyer here. We need medics on the roof right away.”

Another OSI agent appeared from the stairwell — but this one wasn’t out of breath. He jogged over to Avi and Pierre. “We’ve got one of the elevators working again,” he said. “They were all locked off on the fortieth floor, but with the fireman’s key we were able to reactivate one of them once we pried its door open.”

“What happened?” asked Avi.

The agent glanced briefly at Pierre, then looked back at Avi. “It seems a crowbar was dropped from up here into the blades of the helicopter. It caused it to crash.”

Avi nodded and then waved the agent away. When they were alone, he leaned in to Pierre, holding Pierre’s shoulders with his arms. “Did you drop the crowbar?”

Pierre said nothing.

Avi exhaled. “Damn it, Pierre — we don’t cut corners in the OSI. Not anymore. Danielson hadn’t even been charged yet.”

Pierre shrugged slightly. ‘“Justice,”’ he said, his breath coming out raggedly as he quoted another Nobel laureate — at that precise moment, he couldn’t remember which one — ‘“is always delayed and finally done only by mistake.’” He took his right hand off his knee and held it up in the air.

Although they were sheltered from the wind here by the low wall, his arm moved back and forth as if blown by a breeze only it could feel. “Blame it,” said Pierre, “on my Huntington’s.”

Avi’s eyes narrowed and then he nodded, turned, and leaned back against the wall, exhausted not just by the climb but also by years of chasing Ivans and Adolphs and Heinrichs. He closed his eyes and exhaled slowly, waiting for the medics to arrive.