HE STONE table felt cold beneath Katherine Solomon’s back.

Horrifying images of Robert’s death continued to swirl through her mind, along with thoughts of her brother. Is Peter dead, too? The strange knife on the nearby table kept bringing flashes of what might lie in store for her as well. Is this really the end?

Oddly, her thoughts turned abruptly to her research … to Noetic Science … and to her recent breakthroughs. All of it lost … up in smoke. She would never be able to share with the world everything she had learned. Her most shocking discovery had taken place only a few months ago, and the results had the potential to redefine the way humans thought about death. Strangely, thinking now of that experiment … was bringing her an unexpected solace.

As a young girl, Katherine Solomon had often wondered if there was life after death. Does heaven exist? What happens when we die? As she grew older, her studies in science quickly erased any fanciful notions of heaven, hell, or the afterlife. The concept of “life after death,” she came to accept, was a human construct … a fairy tale designed to soften the horrifying truth that was our mortality.

Or so I believed …

A year ago, Katherine and her brother had been discussing one of philosophy’s most enduring questions—the existence of the human soul—specifically the issue of whether or not humans possessed some kind of consciousness capable of survival outside of the body.

They both sensed that such a human soul probably did exist. Most ancient philosophies concurred. Buddhist and Brahminical wisdom endorsed metempsychosis—the transmigration of the soul into a new body after death; Platonists defined the body as a “prison” from which the soul escaped; and the Stoics called the soul apospasma tou theu—“a particle of God”—and believed it was recalled by God upon death.

The existence of the human soul, Katherine noted with some frustration, was probably a concept that would never be scientifically proven. Confirming that a consciousness survived outside the human body after death was akin to exhaling a puff of smoke and hoping to find it years later.

After their discussion, Katherine had a strange notion. Her brother had mentioned the Book of Genesis and its description of the soul as Neshemah—a kind of spiritual “intelligence” that was separate from the body. It occurred to Katherine that the word intelligence suggested the presence of thought. Noetic Science clearly suggested that thoughts had mass, and so it stood to reason, then, that the human soul might therefore also have mass.

Can I weigh a human soul?

The notion was impossible, of course … foolish even to ponder.

It was three days later that Katherine suddenly woke up from a dead sleep and sat bolt upright in bed. She jumped up, drove to her lab, and immediately began work designing an experiment that was both startlingly simple … and frighteningly bold.

She had no idea if it would work, and she decided not to tell Peter about her idea until her work was complete. It took four months, but finally Katherine brought her brother into the lab. She wheeled out a large piece of gear that she had been keeping hidden in the back storage room.

“I designed and built it myself,” she said, showing Peter her invention. “Any guesses?”

Her brother stared at the strange machine. “An incubator?”

Katherine laughed and shook her head, although it was a reasonable guess. The machine did look a bit like the transparent incubators for premature babies one saw in hospitals. This machine, however, was adult size—a long, airtight, clear plastic capsule, like some kind of futuristic sleeping pod. It sat atop a large piece of electronic gear.

“See if this helps you guess,” Katherine said, plugging the contraption into a power source. A digital display lit up on the machine, its numbers jumping around as she carefully calibrated some dials.

When she was done, the display read:

“A scale?” Peter asked, looking puzzled.

“Not just any scale.” Katherine took a tiny scrap of paper off a nearby counter and laid it gently on top of the capsule. The numbers on the display jumped around again and then settled on a new reading.

“High-precision microbalance,” she said. “Resolution down to a few micrograms.”

Peter still looked puzzled. “You built a precise scale for … a person?”

“Exactly.” She lifted the transparent lid on the machine. “If I place a person inside this capsule and close the lid, the individual is in an entirely sealed system. Nothing gets in or out. No gas, no liquid, no dust particles. Nothing can escape—not the person’s breath exhalations, evaporating sweat, body fluids, nothing.”

Peter ran a hand through his thick head of silver hair, a nervous mannerism shared by Katherine. “Hmm … obviously a person would die in there pretty quickly.”

She nodded. “Six minutes or so, depending on their breathing rate.”

He turned to her. “I don’t get it.”

She smiled. “You will.”

Leaving the machine behind, Katherine led Peter into the Cube’s control room and sat him down in front of the plasma wall. She began typing and accessed a series of video files stored on the holographic drives. When the plasma wall flickered to life, the image before them looked like home-video footage.

The camera panned across a modest bedroom with an unmade bed, medication bottles, a respirator, and a heart monitor. Peter looked baffled as the camera kept panning and finally revealed, near the center of the bedroom, Katherine’s scale contraption.

Peter’s eyes widened. “What the … ?”

The capsule’s transparent lid was open, and a very old man in an oxygen mask lay inside. His elderly wife and a hospice worker stood beside the pod. The man’s breathing was labored, and his eyes were closed.

“The man in the capsule was a science teacher of mine at Yale,” Katherine said. “He and I have kept in touch over the years. He’s been very ill. He always said he wanted to donate his body to science, so when I explained my idea for this experiment, he immediately wanted to be a part of it.”

Peter was apparently mute with shock as he stared at the scene unfolding before them.

The hospice worker now turned to the man’s wife. “It’s time. He’s ready.”

The old woman dabbed her tearful eyes and nodded with a resolute calm.

“Okay.”

Very gently, the hospice worker reached into the pod and removed the man’s oxygen mask. The man stirred slightly, but his eyes remained closed. Now the worker wheeled the respirator and other equipment off to the side, leaving the old man in the capsule totally isolated in the center of the room.

The dying man’s wife now approached the pod, leaned down, and gently kissed her husband’s forehead. The old man did not open his eyes, but his lips moved, ever so slightly, into a faint, loving smile.

Without his oxygen mask, the man’s breathing was quickly becoming more labored. The end was obviously near. With an admirable strength and calm, the man’s wife slowly lowered the transparent lid of the capsule and sealed it shut, exactly as Katherine had taught her.

Peter recoiled in alarm. “Katherine, what in the name of God?!”

“It’s okay,” Katherine whispered. “There’s plenty of air in the capsule.” She had seen this video dozens of times now, but it still made her pulse race. She pointed to the scale beneath the dying man’s sealed pod. The digital numbers read:

“That’s his body weight,” Katherine said.

The old man’s breathing became more shallow, and Peter inched forward, transfixed.

“This is what he wanted,” Katherine whispered. “Watch what happens.”

The man’s wife had stepped back and was now seated on the bed, silently looking on with the hospice worker.

Over the course of the next sixty seconds, the man’s shallow breathing grew faster, until all at once, as if the man himself had chosen the moment, he simply took his last breath. Everything stopped.

It was over.

The wife and hospice worker quietly comforted each other.

Nothing else happened.

After a few seconds, Peter glanced over at Katherine in apparent confusion.

Wait for it, she thought, redirecting Peter’s gaze to the capsule’s digital display, which still quietly glowed, showing the dead man’s weight.

Then it happened.

When Peter saw it, he jolted backward, almost falling out of his chair. “But … that’s …” He covered his mouth in shock. “I can’t …”

It was seldom that the great Peter Solomon was speechless. Katherine’s reaction had been similar the first few times she saw what had happened.

Moments after the man’s death, the numbers on the scale had decreased suddenly. The man had become lighter immediately after his death. The weight change was minuscule, but it was measurable … and the implications were utterly mind-boggling.

Katherine recalled writing in her lab notes with a trembling hand: “There seems to exist an invisible ‘material’ that exits the human body at the moment of death. It has quantifiable mass which is unimpeded by physical barriers. I must assume it moves in a dimension I cannot yet perceive.”

From the expression of shock on her brother’s face, Katherine knew he understood the implications. “Katherine …” he stammered, blinking his gray eyes as if to make sure he was not dreaming. “I think you just weighed the human soul.”

There was a long silence between them.

Katherine sensed that her brother was attempting to process all the stark and wondrous ramifications. It will take time. If what they had just witnessed was indeed what it seemed to be—that is, evidence that a soul or consciousness or life force could move outside the realm of the body—then a startling new light had just been shed on countless mystical questions: transmigration, cosmic consciousness, near-death experiences, astral projection, remote viewing, lucid dreaming, and on and on. Medical journals were filled with stories of patients who had died on the operating table, viewed their bodies from above, and then been brought back to life.

Peter was silent, and Katherine now saw he had tears in his eyes. She understood. She had cried, too. Peter and Katherine had lost loved ones, and for anyone in that position, the faintest hint of the human spirit continuing after death brought a glimmer of hope.

He’s thinking of Zachary, Katherine thought, recognizing the deep melancholy in her brother’s eyes. For years Peter had carried the burden of responsibility for his son’s death. He had told Katherine many times that leaving Zachary in prison had been the worst mistake of his life, and that he would never find a way to forgive himself.

A slamming door drew Katherine’s attention, and suddenly she was back in the basement, lying on a cold stone table. The metal door at the top of the ramp had closed loudly, and the tattooed man was coming back down. She could hear him entering one of the rooms down the hall, doing something inside, and then continuing along the hall toward the room she was in. As he entered, she could see that he was pushing something in front of him. Something heavy … on wheels. As he stepped into the light, she stared in disbelief. The tattooed man was pushing a person in a wheelchair.

Intellectually, Katherine’s brain recognized the man in the chair. Emotionally, her mind could barely accept what she was looking at.

Peter?

She didn’t know whether to be overjoyed that her brother was alive … or utterly horrified. Peter’s body had been shaved smooth. His mane of thick silver hair was all gone, as were his eyebrows, and his smooth skin glistened as if it had been oiled. He wore a black silk gown. Where his right hand should have been, he had only a stump, wrapped in a clean, fresh bandage. Her brother’s pain-laden eyes reached out to hers, filled with regret and sorrow.

“Peter!” Her voice cracked.

Her brother tried to speak but made only muffled, guttural noises. Katherine now realized he was bound to the wheelchair and had been gagged.

The tattooed man reached down and gently stroked Peter’s shaved scalp. “I’ve prepared your brother for a great honor. He has a role to play tonight.”

Katherine’s entire body went rigid. No …

“Peter and I will be leaving in a moment, but I thought you’d want to say good-bye.”

“Where are you taking him?” she said weakly.

He smiled. “Peter and I must journey to the sacred mountain. That is where the treasure lies. The Masonic Pyramid has revealed the location. Your friend Robert Langdon was most helpful.”

Katherine looked into her brother’s eyes. “He killed … Robert.”

Her brother’s expression contorted in agony, and he shook his head violently, as if unable to bear any more pain.

“Now, now, Peter,” the man said, again stroking Peter’s scalp. “Don’t let this ruin the moment. Say good-bye to your little sister. This is your final family reunion.”

Katherine felt her mind welling with desperation. “Why are you doing this?!” she shouted at him. “What have we ever done to you?! Why do you hate my family so much?!”

The tattooed man came over and placed his mouth right next to her ear. “I have my reasons, Katherine.” Then he walked to the side table and picked up the strange knife. He brought it over to her and ran the burnished blade across her cheek. “This is arguably the most famous knife in history.”

Katherine knew of no famous knives, but it looked foreboding and ancient. The blade felt razor sharp.

“Don’t worry,” he said. “I have no intention of wasting its power on you. I’m saving it for a more worthy sacrifice … in a more sacred place.” He turned to her brother. “Peter, you recognize this knife, don’t you?”

Her brother’s eyes were wide with a mixture of fear and disbelief.

“Yes, Peter, this ancient artifact still exists. I obtained it at great expense … and I have been saving it for you. At long last, you and I can end our painful journey together.”

With that, he wrapped the knife carefully in a cloth with all of his other items—incense, vials of liquid, white satin cloths, and other ceremonial objects. He then placed the wrapped items inside Robert Langdon’s leather bag along with the Masonic Pyramid and capstone. Katherine looked on helplessly as the man zipped up Langdon’s daybag and turned to her brother.

“Carry this, Peter, would you?” He set the heavy bag on Peter’s lap.

Next, the man walked over to a drawer and began rooting around. She could hear small metal objects clinking. When he returned, he took her right arm, steadying it. Katherine couldn’t see what he was doing, but Peter apparently could, and he again started bucking wildly.

Katherine felt a sudden, sharp pinch in the crook of her right elbow, and an eerie warmth ran down around it. Peter was making anguished, strangled sounds and trying in vain to get out of the heavy chair. Katherine felt a cold numbness spreading through her forearm and fingertips below the elbow.

When the man stepped aside, Katherine saw why her brother was so horrified. The tattooed man had inserted a medical needle into her vein, as if she were giving blood. The needle, however, was not attached to a tube. Instead, her blood was now flowing freely out of it … running down her elbow, forearm, and onto the stone table.

“A human hourglass,” the man said, turning to Peter. “In a short while, when I ask you to play your role, I want you to picture Katherine … dying alone here in the dark.”

Peter’s expression was one of total torment.

“She will stay alive,” the man said, “for about an hour or so. If you cooperate with me quickly, I will have enough time to save her. Of course, if you resist me at all … your sister will die here alone in the dark.”

Peter bellowed unintelligibly through his gag.

“I know, I know,” the tattooed man said, placing a hand on Peter’s shoulder, “this is hard for you. But it shouldn’t be. After all, this is not the first time you will abandon a family member.” He paused, bending over and whispering in Peter’s ear. “I’m thinking, of course, of your son, Zachary, in Soganlik prison.”

Peter pulled against his restraints and let out another muffled scream through the cloth in his mouth.

“Stop it!” Katherine shouted.

“I remember that night well,” the man taunted as he finished packing. “I heard the whole thing. The warden offered to let your son go, but you chose to teach Zachary a lesson … by abandoning him. Your boy learned his lesson, all right, didn’t he?” The man smiled. “His loss … was my gain.”

The man now retrieved a linen cloth and stuffed it deep into Katherine’s mouth. “Death,” he whispered to her, “should be a quiet thing.”

Peter struggled violently. Without another word, the tattooed man slowly backed Peter’s wheelchair out of the room, giving Peter a long, last look at his sister. Katherine and Peter locked eyes one final time.

Then he was gone.

Katherine could hear them going up the ramp and through the metal door. As they exited, she heard the tattooed man lock the metal door behind him and continue on through the painting of the Three Graces. A few minutes later, she heard a car start.

Then the mansion fell silent.

All alone in the dark, Katherine lay bleeding.

OBERT LANGDON’S mind hovered in an endless abyss.

No light. No sound. No feeling.

Only an infinite and silent void.

Softness.

Weightlessness.

His body had released him. He was untethered.

The physical world had ceased to exist. Time had ceased to exist.

He was pure consciousness now … a fleshless sentience suspended in the emptiness of a vast universe.