Once, when his father was alive, Langdon had heard his mom begging his father to "stop and smell the roses." That year, Langdon bought his father a tiny blown-glass rose for Christmas. It was the most beautiful thing Langdon had ever seen… the way the sun caught it, throwing a rainbow of colors on the wall. "It's lovely," his father had said when he opened it, kissing Robert on the forehead. "Let's find a safe spot for it." Then his father had carefully placed the rose on a high dusty shelf in the darkest corner of the living room. A few days later, Langdon got a stool, retrieved the rose, and took it back to the store. His father never noticed it was gone.

Langdon strode silently behind Vittoria and Kohler as they moved back into the main atrium where Langdon's bizarre visit had begun. Vittoria's legs drove in fluid efficiency -- like an Olympic diver -- a potency, Langdon figured, no doubt born from the flexibility and control of yoga. He could hear her breathing slowly and deliberately, as if somehow trying to filter her grief.

Langdon wanted to say something to her, offer his sympathy. He too had once felt the abrupt hollowness of unexpectedly losing a parent. He remembered the funeral mostly, rainy and gray. Two days after his twelfth birthday. The house was filled with gray-suited men from the office, men who squeezed his hand too hard when they shook it. They were all mumbling words like cardiac and stress. His mother joked through teary eyes that she'd always been able to follow the stock market simply by holding her husband's hand… his pulse her own private ticker tape.

The ping of an elevator pulled Langdon back to the present. Vittoria and Kohler were in front of him, boarding the lift. Langdon hesitated outside the open doors.

"Dr. Vetra's lab is subterranean," Kohler said.

"Not at all," Langdon said, forcing himself toward the cramped carriage. He only used elevators when absolutely necessary. He preferred the more open spaces of stairwells.

"Six stories," Kohler said blankly, like an analytical engine.

"Is something wrong?" Kohler asked, sounding more impatient than concerned.

"What's LHC stand for?" Langdon asked, trying not to sound nervous.

Langdon pictured the darkness of the empty shaft below them. He tried to block it out by staring at the numbered display of changing floors. Oddly, the elevator showed only two stops. GROUND LEVEL and LHC.

"Large Hadron Collider," Kohler said. "A particle accelerator."

Wonderful, Langdon thought as he stepped across the cleft, feeling an icy wind churn up from the depths of the shaft. The doors closed, and the car began to descend.

Particle accelerator? Langdon was vaguely familiar with the term. He had first heard it over dinner with some colleagues at Dunster House in Cambridge. A physicist friend of theirs, Bob Brownell, had arrived for dinner one night in a rage.

"The bastards canceled it!" Brownell cursed.

"The SSC!"

Someone shrugged. "I didn't know Harvard was building one."

"Canceled what?" they all asked.

"The what?"

"The Superconducting Super Collider!"

"Not Harvard!" he exclaimed. "The U. S.! It was going to be the world's most powerful particle accelerator! One of the most important scientific projects of the century! Two billion dollars into it and the Senate sacks the project! Damn Bible-Belt lobbyists!"

When Brownell finally calmed down, he explained that a particle accelerator was a large, circular tube through which subatomic particles were accelerated. Magnets in the tube turned on and off in rapid succession to "push" particles around and around until they reached tremendous velocities. Fully accelerated particles circled the tube at over 180,000 miles per second.

When the elevator thumped to a stop, Langdon was relieved to feel terra firma beneath his feet. But when the doors slid open, his relief evaporated. Robert Langdon found himself standing once again in a totally alien world.

"But that's almost the speed of light," one of the professors exclaimed.

Harvard's Poet in Residence, a quiet man named Charles Pratt, did not look impressed. "It sounds to me," he said, "like a rather Neanderthal approach to science… akin to smashing clocks together to discern their internal workings."

Brownell dropped his fork and stormed out of the room.

"Damn right," Brownell said. He went on to say that by accelerating two particles in opposite directions around the tube and then colliding them, scientists could shatter the particles into their constituent parts and get a glimpse of nature's most fundamental components. "Particle accelerators," Brownell declared, "are critical to the future of science. Colliding particles is the key to understanding the building blocks of the universe."

So CERN has a particle accelerator? Langdon thought, as the elevator dropped. A circular tube for smashing particles. He wondered why they had buried it underground.

Vittoria remained hushed as she exited the elevator and strode off without hesitation into the darkness without them. Overhead the flourescents flickered on to light her path. The effect was unsettling, Langdon thought, as if the tunnel were alive… anticipating her every move. Langdon and Kohler followed, trailing a distance behind. The lights extinguished automatically behind them.

The passageway stretched out indefinitely in both directions, left and right. It was a smooth cement tunnel, wide enough to allow passage of an eighteen wheeler. Brightly lit where they stood, the corridor turned pitch black farther down. A damp wind rustled out of the darkness -- an unsettling reminder that they were now deep in the earth. Langdon could almost sense the weight of the dirt and stone now hanging above his head. For an instant he was nine years old… the darkness forcing him back… back to the five hours of crushing blackness that haunted him still. Clenching his fists, he fought it off.

"This particle accelerator," Langdon said quietly. "It's down this tunnel someplace?"

"This acceleratoris a circle," Kohler said. "It appears straight, but that is an optical illusion. The circumference of this tunnel is so large that the curve is imperceptible -- like that of the earth."

Langdon eyed the tube, confused. "That's the accelerator?" The device looked nothing like he had imagined. It was perfectly straight, about three feet in diameter, and extended horizontally the visible length of the tunnel before disappearing into the darkness. Looks more like a high-tech sewer, Langdon thought. "I thought particle accelerators were circular."

Langdon was flabbergasted. This is a circle? "But… it must be enormous!"

"The LHC is the largest machine in the world."

"That's it there." Kohler motioned to his left where a polished, chrome tube ran along the tunnel's inner wall.

Langdon did a double take. He remembered the CERN driver saying something about a huge machine buried in the earth. But --

"It is over eight kilometers in diameter… and twenty-seven kilometers long."

Langdon's head whipped around. "Twenty-seven kilometers?" He stared at the director and then turned and looked into the darkened tunnel before him. "This tunnel is twenty-seven kilometers long? That's… that's over sixteen miles!"

Kohler shrugged. "Sometimes to find truth, one must move mountains."

Kohler nodded. "Bored in a perfect circle. It extends all the way into France before curving back here to this spot. Fully accelerated particles will circle the tube more than ten thousand times in a single second before they collide."

Langdon's legs felt rubbery as he stared down the gaping tunnel. "You're telling me that CERN dug out millions of tons of earth just to smash tiny particles?"