"The protein in Airifan affects alpha-one ant.i.trypsin production in the liver. But we do not use it that way in the drug. Our goal was asthma and emphysema, two of the major diseases of our time. We could not step through a door into that room."

"What are you saying?"

"I'm saying, we have it."

Shane pulled over and stared at him. "You have what?"

"A protein that solves for alpha-one ant.i.trypsin deficiency. We have it," Prajuk a.s.sured him. "We just left it behind a door."

4.

In August, Caleb fell off of Engineer Mountain.

He was thirteen thousand feet up in the air, just underneath the belly of the clouds, seventy-one miles into the Hardrock 100.

The race had begun in the antediluvian mining town of Silverton, Colorado. It looped counterclockwise through Lake City, Ouray, Telluride, and back to Silverton, over thirteen peaks of the San Juans. Last year, his descents from the snowcapped summits had given him trouble. The trick was to slide down the snow on one hip, but the powder hid sharp rocks, and Caleb never managed the necessary abandon. He had finished twenty-seventh. All last winter, he had practiced proper glissades.

So at dawn Caleb stood in front of the Silverton high school along with 140 other runners, from their twenties to their sixties, staring ahead at the mountain range. A few hopped up and down to warm up in the mist; most conserved their energy. Just ahead of him he recognized Julien Chorier, Betsy Nye, a few other top-ten finishers from last year. He also spotted other runners whom he had witnessed sobbing and vomiting along the trails.

In his hand Caleb gripped lightweight trekking poles for the snow and ice. Across his shoulders he wore a small orange backpack filled with energy gel, sunblock, shades, and water. Everything else he would need lay in drop bags strategically placed inside the aid stations.

Mack had called them together in the dark, held their hands, and gave them some Whitman: "'Not I, nor anyone else, can travel this road for you. You must travel it by yourself. It is not far. It is within reach.'" He nodded, then burst into a wild grin. "'Each of us inevitable! Each of us limitless!'"

They had held each other, heads bent. A runner named Joel Zucker had died of a brain aneurysm on this course in 1999; Rae reminded them all to stay alert. When the gun sounded, Caleb sprinted through the narrow streets of Silverton, past Runner's World magazine photographers, cheering fans, and curious townsfolk. Behind him Kyle Meltzer, who had won more than a few ultras, shook his head at whoever was so foolish as to run off the start. But Caleb never walked the start of a race, he knew no other way than to gallop into the distance, as he had in Issaquah as a boy, until he had no choice but to slow.

A few miles into the mountains, Caleb plunged into Little Giant Basin. It was like running down the inside of a deep bowl of jade. Caleb found his rhythm, breathed deeply, and trotted across the lush green field and up the other side of the basin.

He was the first to the Arrastra stream. The smell of salmon filled the frigid water. It felt good to be shocked alive. When he emerged and began jogging up the trail in his wet shoes, and his calves awoke, Caleb felt as happy as he guessed was possible in the world.

He drank his water and ran past a cairn toward steep beige cliffs. He ascended up to the scree fields, rock crumbling beneath him; he might slip and shatter his legs with any step. Below, he saw the magnificence of Cunningham Gulch, its ribbons of white snow winding through dark brown granite.

The first aid station appeared on his left. A good crowd wearing Gore-Tex sh.e.l.ls of various neons stood by the blue nylon tent, clapping for him. A few held video cameras, and there seemed to be lots of parents and children. It looked like a stranger's family reunion, and Caleb had the mind to run past it. But then Alice appeared, beckoning him inside.

"Nice race. But slow down," she told him, handing him a banana milkshake.

Caleb nodded, sat on a bench, and stared down at his wet Montrails. Alice rubbed sunscreen onto his reddening shoulders and refilled his water bottle.

"I'm pacing you this leg," she informed him.

He nodded.

"Meltzer," Alice gestured.

Caleb watched him approach. He was walking quickly, apparently taking in the glory of the day. He must have run and jogged to be here this quickly, but he did not seem to have broken a sweat yet. Caleb found a baseball hat in his pack, grabbed his poles, and ran out with Alice onto the trail toward Green Mountain. Leaving, he heard someone say something about sleet.

The course grew steeper, punishing his quads and calves. b.u.t.terflies brushed against his shoulders. Alice held him back as they ascended toward the white snowpack; anytime he began to move faster she touched his shoulder. Some miles later they were confronted by a herd of goats ambling across the path. Just to their left was a sheer four-hundred-foot drop, and on their right a granite wall. There was nowhere to go, Alice said, flattening her back nervously against the rock. Caleb plunged straight through the herd, causing a braying that echoed down into the valley.

As the trail rose, he concentrated on his heart rate. Monitoring his body took all of his attention, leaving none for such tangents as the contemplation of pain. Even as he starved, he felt his soul being fed. He took his first steps on snow.

And then the course shot steeply downward. At Maggie Gulch he ran through a summer field covered in orange wildflowers, while a microclimate of a snowstorm drifted just ten feet away. Alice handed him an electrolyte gel. His stomach clenched unhappily; he had the experience of these gels causing him trouble.

They reached the end of the first leg, two hours under the cutoff. Caleb checked in with race officials at the Sherman station. He had lost three pounds; seven was an automatic disqualification. Alice kissed his cheek, and Leigh, willowy and red-faced, walked over with climbing equipment and called to him as to a puppy, "Come on, Caley!"

Some miles later they moved into a grove of aspens, where black flies flew from the conifer and bit his neck. He watched Handies Peak materialize ahead of him.

Leigh whispered, "I dropped here last year."

He recalled it. A severe thunderstorm had swept in, crushing the trail to mud, pelting the climbers with hail. Luckily, he had been on his way to Telluride by then.

They stopped to pull crampons from their packs and over their shoes. He shook loose his trekking poles, and their points plunged through wet tufts of frozen gra.s.s and snowpack, scattering loose stones beneath him. He called a warning to Leigh behind him and pushed himself skyward. It was not his job to worry about her.

The ascent up to fourteen thousand feet took longer than he had antic.i.p.ated. Below them the approaching runners seemed to be coming at him in one large pack. He began to visualize his old flowcharts from his days at InterFinancial, going over them as his legs pushed against the granite, lost in math and equations.

At the summit the air around him was as pure as newborn breath. Fluttering orange flags pointed them toward a narrow natural bridge, made of rock, covered in snow, which connected them to the south face of the next pa.s.s. The drop below them was astonishing. They crossed carefully, hovering eleven thousand feet in the air with no guardrail, suspended above the world.

On the other side, the trail dropped abruptly into boulder fields. Without thinking about it he executed a perfect glissade down the snow, ice lacerating his cheeks. Halfway down, he turned his head, saw Leigh just behind him, and Kyle Meltzer at the top.

At the next aid station, Kevin Yu was waiting for him with bigger shoes. This was good; his feet had swelled half a size. Where was June, he thought? She wasn't quite ready to run Hardrock, so he imagined Mack had told her to pace. He felt the need of her as the sky began to dim.

Caleb slammed a nauseating glucose polymer mix. He considered his situation. His fifth mountain peak confronted him. He had been running nonstop for sixteen hours. He should be fine.

He followed Kevin up the incline ahead. Maybe June was meeting him in Telluride, and they would have time together until the dawn. He was visualizing this when he jammed a foot under a large purple rock. Nerve pain shot into his right knee like fire and he fell hard to the snowy ground.

Kevin caught up, panting. He kneeled and looked at Caleb's leg. His kneecap had shifted out of position; it bulged ugly and rocklike against his stretched skin. Kevin touched it and Caleb shut his eyes tight, the pain blinding. His poles slipped from his hands and rolled down twenty yards. Meltzer jogged ahead into the dusk. Caleb stared after him, sweat soaking through his shirt. He started shivering.

"They have medics at Grouse. Should we go back?"

Runners began pa.s.sing, some nodded in empathy but most were too focused to notice. If Caleb were helped to move in any way, it would be a disqualification. Kevin looked to him, asking with his eyes if he should do it. Caleb nodded grimly.

And Kevin raised the flat of his hand and slammed it against Caleb's kneecap. Once. Twice. Caleb screamed. Red agony tore him asunder as if he had stepped on a third rail.

"Sorry," Kevin muttered, frowning.

He hit it again, harder this time, and the kneecap shifted back into place with an audible click.

This moment, right now, was the finish line. If he could not cross it, then no other banner mattered. Caleb knew enough to understand that the longer he sat here, the more his knee would swell and stiffen. It was either keep it loose, or end this. So he stood gently, hopped on his left leg, took a very long breath, visualizing kinetic energy flowing from the trees into his kneecap, and took a full step on his right leg. The pain was horrific. Somehow he did not collapse, and he tried another step. Eventually the pain would subside, he knew, but it might take miles.

Kevin stood beside him. "Engineer's gonna hurt, bro," he said seriously.

The sun fell behind the mountain, plunging them into a sudden and complete darkness. Kevin took two headlamps with Petzl lights and pulled them onto his head and Caleb's. Only the five yards of trail directly in front of him were visible in the circle of yellow light. Moving into it felt like the night swimming he had done in Issaquah. A primal fear pushed against a sense of deep trust and faith, a sense of the unknowable.

After some miles of ascent, the pain in his knee began to subside. Tomorrow it would be a very different story, he knew, but right now it was nearly numb. He looked below him. A wave of golden lights hovered below like j.a.panese lanterns. They were the headlamps of other runners weaving through the darkness. A beautiful sense of camaraderie overtook him.

Engineer became a pure climb, hand over hand, fingers tugging at rock and dirt. He was fully engaged, focused entirely on each step forward, and the pain in his body, his lungs, his legs, fell away.

"Hey," Kevin called, unable to match him.

But he moved faster, almost gliding. He was deep-diving into uncharted regions.

He was shocked, therefore, to see his brother sprint by in his ratty Grateful Dead Tacoma Dome '88 shirt.

"Hey," Shane called, grinning.

Caleb stopped, awed. "How did you get here?"

"I wanted to see what you love about this."

"And?"

"It sucks," Shane p.r.o.nounced. "Everything hurts."

"Why haven't I heard from you?" He tried to catch his breath. "Why don't you help us?"

"I have an answer," Shane announced brightly. He seemed full of energy. "But you have to follow me." He waved and took off up the mountain.

When he understood there was no Shane, only darkness and his frail body, Caleb touched a solitude that shook him. He had been broken at Ma.s.sanutten, where he had suffered hypothermia, and at the Wasatch 100 in Utah, when he had thought he might die of fever, but he had never felt this alone.

Miles below, the lights of Ouray blinked like buoys. A sudden explosion of lightning ripped across the sky, and rain pounded over him. He scrambled up in the dark, trying to reach the peak before the dirt turned to mud and began to slide. At the top he found solid earth, curving away from the sudden storm. Kevin was long behind him now.

He decided to catch up with Shane. He had more to ask him.

He must have slipped in the dirt. His exhausted body lurched helplessly left, and unable to right himself he skidded off the edge, frantically clutching at the sheer mountain rock and teasing tufts of green along the side, fingernails tearing along the granite.

He tumbled down the steep incline, his legs kicked madly looking for a way to stop, his fingers clutched at loose rock and air, and then, twenty feet down, he hit a protruding ledge of granite. He landed on his face, b.l.o.o.d.ying his mouth, and lay breathless. A foot to his left was a sheer plummet of thousands of feet.

Behind his closed eyes he felt like he was falling. Finally he opened them to the gray shelf and dared to look down. In the breaking light he could make out the corkscrew trail below, and antlike blurs of runners moving up the mountain.

Carefully Caleb turned, sc.r.a.ping his elbow, and lay on his back. Above, a sunrise broke in feverish hues. He could see the red sky, and shadows of people jogging past the point where he had slipped. He tried to call out to them, but an agoraphobic shiver overtook him, he feared yelling might shake his body over the narrow shelf, and so he lay silently, pulling deep breaths.

On the wind then he smelled June's skin. He heard her voice, whispering an affirmation. And then Lily came to him. Her laugh, her own sweet scent, were all around him, as clear as air. He had not noticed how deeply they had permeated him, how much he needed them both now, not only to run, but to even breathe.

Caleb had been in a restaurant.

His suit had been gray, conservative. His hair had been short. He had been pale, and a paunch had overtaken his belt. He had been nursing a breakfast of granola and coffee with two partners from InterFinancial and new clients from an Ohio packaged meats company, at a financial district restaurant. Caleb had not been saying very much; he was the a.n.a.lytics guy. The sell was for his colleagues.

They were discussing the InterFinancial process when a roar of background noise rose from outside. Caleb turned and looked out the plate-gla.s.s window, and saw a woman in a white blouse running with her arms out in front of her face.

She was followed by other people, coming from the same southerly direction. An older man, his eyes wide, screaming. Three black women sprinting with their heads down. Caleb turned back to his table to comment, but by then there was something in the air that forced them all outside. He saw the enormous crowd running right at him, jumped backward, out of its rush. That was when he noticed the rolling panzers of black smoke behind them, coming fast.

Caleb started to run. Instinctively, he reverted to the quick long-legged run of his youth. People were convulsed, sobbing, pointing upward. Confused, Caleb followed their hands as they lifted to the firmament.

Caleb grasped how close he was to being swallowed by the chemical smoke pouring over them. He ran as hard as he could with the stricken crowd until it broke into pieces like an army in retreat. Near Mott he was swept into a platoon pushing relentlessly toward the water.

The Brooklyn Bridge loomed ahead. In the windows of the endless maroon housing projects, people pressed at the gla.s.s, gesturing madly. Caleb never turned around to look at the devastated skyline, at the collapsed people on the street, or the screaming engines headed toward the smoke, and in this he was nearly alone.

Crossing the bridge he became deeply aware of its swaying; he felt sure that it would collapse and he would plummet. On the other side sirens blazed, blue lights flashed, the policemen's faces were tilted to the sky.

On the other side, he stopped. He had not considered direction, or how far he was from home. He needed to get back to the West Side. He spied a subway stop and descended its dark steps, but the trains had been shut down, and he stood at the locked gate searching inside the blackness for something alive.

He reemerged onto the smoke-filled street and finally watched the chaos across the river. Around him those he had run with were embraced by their families, friends, and neighbors. Caleb stood alone in his filthy shirt, his sweat-strewn face turned toward the burning, closed city, and understood that, for a long time, he had been running the wrong way.

A week afterward, Caleb wandered into a bookstore.

His office was of course closed, and though he was meant to be working from his apartment, he felt a need to be near people. He flipped absently through books on ice, the Giants, Israel, looking for something to pull him into its world. Nothing engaged until, wandering through a dim aisle with a green plastic sign reading SPORTS, a cover photograph stopped him. On it, an elfin hippie looked to the camera with an expression of total, perfect confidence that reminded him of Shane.

The man wore an orange and blue tie-dyed T-shirt, and a scraggly black beard which highlighted eyes the clear blue of an infant's. He stood before the peak of a mountain. Across his chest, in proud yellow letters, read the words YOU CAN RUN 100 MILES!

Caleb took up a copy, sat down on the worn carpet, pulled his knees to his chest, and began to read.

"Kinetic Energy is the energy that we build when we move. This is the energy that our body uses to repair its cells, to heal itself. It is blood's sister. And yet we deprive ourselves of this vital force in fatal amounts.

"The faster you build up your stores of kinetic energy, the faster your body will revert to the perfect machine it was born to be. You will be able to heal without the use of toxic drugs. You will be able to live on four hours of sleep a night, extending your waking life by almost a third. You will live without exhaustion, without doubt, without illness. You will experience a life totally unlike the one you know now. And all you have to do is run."

Caleb flipped over the book. Its back cover showed another picture of the man, running up a mountain trail. Underneath it said: "John 'Mack' McConnell is the founder of the Happy Trails Running Club in Boulder, Colorado. Runners coached by McConnell have dominated ultramarathons for the last decade."

Caleb purchased the book and went back to his apartment feeling oddly awake. That evening, for the first time in a year, he went for a run through Riverside Park. Lactic acid seared his chest from the start; at three miles he sat down on a bench, chest heaving. All around him the world was in trauma, and yet for the last hour, he had been completely immersed in something else entirely, and not given it a thought.

When the airports opened, Caleb packed a small bag and flew to Colorado. His flight had been a mess, the paranoia of airport security outmatched only by that of his fellow pa.s.sengers.

After the tension at LaGuardia and Denver International, he felt the peace of Boulder immediately. The mountains seemed almost too present, and he walked with his eyes focused on the streets, until he acclimated to them.

Caleb checked into a Marriott on Canyon and went for a jog. He made it to Flagstaff and meandered slowly into the dirt trails. The sun was strong, bathing the woods in olive, ginger, and gold. He loved how these trails were as alive as Manhattan. Birds, lizards, runners, pa.s.sed him in all directions. His lungs gave out after three miles in the unfamiliar thin air, and he stood with his hands pulling down on his shorts, watching the sun lower behind the Front Range.

The next morning he went without his coffee, walked to Fleet Feet, and asked one of the employees about the Happy Trails Running Club. The name seemed to inspire suspicion.

"I heard they all live together," a salesgirl nodded her head, tying his new Salomon trail running shoes.

A pockmarked kid told him, "They're all at the Rocking Horse on Thursdays."

All week, Caleb ran beneath the autumn sky. He taught himself Mack's running form as described in the book, landing lightly on the b.a.l.l.s of his feet, never his heels, body straight, running on a treadmill by a mirror in the Marriott gym until he felt confident of his posture. He ate Boulder food, organic, less meat. The following Thursday, Caleb ran six miles in the deep woods. At dusk he emerged and went straight to the Rocking Horse Tavern.

His nose was running as he hesitated by a pile of free local newspapers in the doorway. Inside, twenty people in old T-shirts relaxed in a cl.u.s.ter amidst the damp thick pub smell, conversing noisily at round wood tables, cradling pints of dark beer.

He inhaled as he recognized John McConnell seated at a window table. Mack was digressing on his unique method of tying shoes; he had found some pattern to the laces that he swore added milliseconds to one's time. When he finished, Mack pounded a pint in two swallows and shot his eyes unexpectedly straight to Caleb.