Page 110 of The Secret of Secrets (Robert Langdon #6)

“I didn’t,” Katherine replied. “There is no solution but to wait. Biological growth takes time. Evolution takes time. And yet somehow…” She studied a series of graphs, shaking her head.

“They’ve accelerated the process with remarkable speed.

In a year, they’ve done what should have taken at least a decade.

The question…is how ?” She kept flipping pages, passing one on which appeared a tiny headshot of a younger Sasha Vesna with long blond hair.

“I have a different question,” Langdon said. “If Sasha is patient number two …”

Katherine glanced up. “Right, then who is patient number one ?”

She immediately began flipping backward through the binder, looking for information on patient number one, who Langdon assumed was most likely the Russian epilepsy patient, Dmitri, from the same institution as Sasha.

“This is strange,” Katherine said. “I don’t see any section with data on any other—oh, wait—here it is. It’s much shorter. I missed it.”

The section included assorted data, graphs, and a similarly eerie X-ray of the subject’s brain showing an implanted chip and neural mesh.

The footer read:

PATIENT #001 / SYSEVICH

Sysevich certainly sounds Russian, Langdon thought.

“Handsome man,” Katherine said, having turned to a page bearing a small headshot of a striking, square-jawed man with curly black hair.

His features were clearly Slavic, sturdy and commanding, and yet his eyes had an unsettlingly lifeless gaze.

“This guy was clearly implanted with the same chip as Sasha,” Katherine said, still reading.

“But it’s weird—there’s absolutely no data post-op. Nothing.”

“We can talk on the way out,” Langdon said, heading for the revolving door. “We’ve got to get out of here.”

Katherine closed the binder and slipped it into her shoulder bag. “I hate to say it, but his records end too abruptly. Zero follow-up. It’s like they put the chip in, and…something went wrong. Maybe he died. ”

The thought was disturbing, and yet it added additional ammunition to the leverage they would have; if the CIA experimented on and killed an unsuspecting Russian epilepsy patient, the diplomatic fallout could have dire repercussions in a world already on edge.

As they pushed through the revolving door back into the hallway, Langdon was reassured to find the corridor pitch-black, its lights having timed out while they were in the lab.

We’re still alone down here.

The floor lighting immediately came on, and Langdon and Katherine turned back toward the double doors through which they had come.

They had taken only a few steps when Katherine grabbed Langdon’s arm. “Look!” she whispered, pointing dead ahead to the doors with the oval windows.

Langdon had seen it too.

The lights on the other side of that door had just blazed to life.

Having completed his thorough search of the medical area, Finch had continued around the corner, where the floor lighting came on to illuminate his path to the double doors at the end of the hall.

Taking no chances, he took a moment to stick his head into Immersive Computing, where he was relieved to find all the VR chairs empty and helmets in order.

Then he saw the desk chair on its side.

And the cracked glass in the computer room window.

Normally Finch would have dashed over to check the computer, but he had just had a far more alarming realization—a delayed reaction to something he had glimpsed only moments earlier in the hallway…a soft glow coming through the oval windows of the double doors.

The lights in the RTD hallway were on.

Someone is coming!

Whether a cleaning crew, a security guard, or worse, Langdon knew he and Katherine could not afford to be seen. Unfortunately, they were trapped in a dead-end corridor with no way out except the way they had come.

Langdon rushed back toward the RTD lab, hoping to find somewhere to hide, but as he neared the clean room door, he realized Katherine had stopped in the middle of the hallway and was pointing at the floor. “Robert,” she whispered. “These are tire marks!”

Langdon had seen the marks earlier—a trail of scuff marks worn into the polished floor by the treads of the forklift.

To his confusion, Katherine immediately sprinted past him, waving for him to follow her toward the dead end. What is she doing?! There’s no exit! A moment later, Langdon spotted what Katherine had seen: the wear of tire tracks continued down the hallway and disappeared… beneath the far wall.

Impossible…unless…

Langdon broke into a full sprint, pulling even with Katherine fifteen yards from the end of the hall. He spotted the electric eye and ran toward it, waving to activate the sensor. The entire wall began to slide, retracting smoothly to the left, revealing another section of darkened corridor beyond.

The air emerging from the opening was noticeably colder.

Without breaking stride, he and Katherine ran through the opening and within a few yards plunged into sudden darkness. They came to a stop at a metal railing just as the retracting wall closed behind them.

Soft lighting swelled to reveal their surroundings.

Langdon was startled to see they were standing atop a concrete ramp that wound downward around the perimeter of a narrow shaft.

As he peered over the railing into the darkness below, he realized that Threshold was indeed considerably larger than what they had seen…

and it continued in an unnerving direction.

Down.