When the airlock of the mining vessel Geongon opened, the air was different. Not the air inside the Domain, but the purified air of the relay station's docking bay. Jeongho pulled off his helmet and drew a breath. His lungs refused it. A fit of coughing tore out of him. He braced a hand against the floor. The feel of his palm against the metal grating was strange. Too hard. No—his palm was too soft. Over the 6 weeks he'd spent inside the Domain, the sensation in his fingertips had changed, and it wasn't coming back. The docking bay's fluorescent lights stabbed at his eyes. There was no light like this inside the Domain. In there the energy levels of the photons were subtly different, so all light skewed toward the red. Eyes that had adapted to red light for 6 weeks couldn't bear white light. Jeongho squinted and looked at the docking bay wall. The metal was reflecting the fluorescent glare. The reflected light left a pain like burst capillaries in his eyes. Inside the Domain, light was soft as water. Here it was a blade. Jeongho rubbed his eyes. They watered. Not emotion—reflex.
Jeongho walked with a hand on the docking bay wall. His legs were heavy. He didn't know if heavy was even the right word. The station's artificial gravity was 0.3g. Inside the Domain the gravitational constant itself was different, so the same 0.3g felt different in the body. Gravity inside the Domain had been soft. The force meeting his bones had felt viscous, almost. Gravity here was sharp. Like it was jabbing straight into the bone. Jeongho found a scale and stepped onto it. 71.2 kilograms. Before he went in, he'd been 73 kilograms. 1.8 kilograms gone. Not from lack of food. Inside the Domain the protein folding of his muscle fibers had changed, and his muscles burned energy in a different way. Out here the muscles couldn't find their original folding, and their contraction-relaxation efficiency dropped. The muscle hadn't shrunk—the way it worked had changed.
He left the docking bay and walked the corridor. The relay station Boundary was humanity's last outpost, positioned beyond the Kuiper Belt. 30 astronomical units out from Neptune's orbit. 47 permanent personnel. 22 of them mining crew. Half a year ago there had been 26. 4 fewer now. 2 had returned when their contracts expired, 1 had died in an accident inside the Domain, and 1 had failed to readapt to Earth's atmosphere after return and died in transit. His name was Choi Yeongsu. A fifth-time entrant. His oxygen saturation had begun to fall aboard the return vessel, he'd lost consciousness, and he hadn't woken. The death notice was still tacked to the corridor's bulletin board. No one had taken it down. The paper had gone soggy and stuck fast in the damp. The corridor floor was iron grating, so footsteps rang. Jeongho's footsteps sounded different than before. Lighter. The force his soles pushed against the grating had weakened.
Jeongho stopped in front of the examination room. A sign on the door read 'Mandatory Post-Return Physical.' When he opened the door, the doctor, Nahyeon, was sitting in front of a monitor. Nahyeon looked up at him. Her eyes swept over his face. Her gaze stopped at his eyes.
"Your pupils have changed color."
Jeongho looked for a mirror. Nahyeon handed him a small one from the table. He peered into it. His irises had originally been brown. Now there were red flecks scattered through the brown. The melanin structure of the iris had changed. Because the energy levels of molecular bonds were different inside the Domain, the folding structure of the pigment proteins had shifted, subtly. Out here it should have gone back. But it hadn't.
Nahyeon drew a blood sample. When the needle punctured the vein, the pain was severe. Inside the Domain the threshold of his pain receptors had risen. Out here the threshold should have returned to normal, but the instant the needle pierced his skin, Jeongho clenched his teeth. Before, he wouldn't have reacted to this much. The threshold had dropped. Not gone back—shifted the opposite way.
"This is your fourth entry, right?"
Nahyeon asked. His mining record was up on the monitor.
"Yeah."
"Through the third, your readings came back to normal. This time—"
Nahyeon turned the monitor toward him. The oxygen-binding curve of the hemoglobin in his blood was displayed. The normal curve and Jeongho's curve lay side by side. His curve had shifted to the left. His oxygen affinity had risen. Inside the Domain the binding energy of the oxygen molecule was different, so his hemoglobin had adapted toward grabbing oxygen more easily. Out here it should have reversed. But Jeongho's hemoglobin was holding on to the binding mode of the Domain.
"With this curve at Earth's atmospheric pressure—"
Nahyeon cut herself off. Jeongho watched her.
"Say it."
"Oxygen doesn't get delivered to the tissue. The cells can't take up oxygen."
Jeongho's hand moved on his knee. Clenching into a fist, opening again.
"You're saying I can't go back to Earth?"
Nahyeon didn't answer. She looked at the monitor. Jeongho looked at it too. The curves glowed on the screen. The distance between the two curves was the distance between Jeongho and Earth. On a graph measured in millimeters, his body had drifted away from Earth.
Jeongho left the examination room and went to the cargo bay. Ore mined out at Geongon sat packed in a container. He looked in through the container's observation window. Ore dug out inside the Domain. What had glowed violet inside the Domain was nothing but a lump of black rock here. Inside the Domain, this ore had a conductivity 340 times that of copper. A room-temperature superconductor. Brought outside, its conductivity dropped to that of ordinary basalt. A material that worked only in the Domain, where the physical constants were different. So the processing had to be finished inside the Domain, which meant staying inside the Domain a long time, and the longer you stayed, the more your body changed. Mining inside the Domain was a kind of transaction. A transaction in which you got the material and gave up your body. The problem was that the terms of the transaction accumulated. On the 1st run your skin pigment changed, on the 2nd your sensory thresholds shifted, on the 3rd your temperature regulation wavered, on the 4th the chemistry of your blood turned different. The records past the 5th run were kept in a locked filing cabinet in the relay station's infirmary. Jeongho knew that cabinet existed, but he had never opened it. He didn't want to.
Jeongho stood at the desk of the cargo office. Behind the desk sat Seokjin, the clerk. Seokjin was logging the weight and purity of the ore.
"84 kilograms, 92 percent purity."
Seokjin held out a slip.
"Settlement 14 days from now, on head-office transfer terms."
Jeongho took the slip. He looked at the amount. 42 million won, base pay included. His daughter's surgery cost 120 million won. Over 3 entries he had gathered 78 million won. Add this one and it came to 120 million won. Exactly. Jeongho's finger stopped on the slip. He looked at the number again. 120 million won. Surgery. Daughter.
Jeongho went back to his quarters. It was a narrow room. A bed and a table. On the table stood a single photograph. A photo of his daughter, Yuna. Yuna was 9 this year. The last time he had seen her was 2 years ago. The day before he left, he had held Yuna's hand in the hospital lobby. Yuna's hand was small. Her fingers were thin. A child with a defect in her heart had cold fingertips. Jeongho had wrapped Yuna's hand in both of his and made it warm. His body temperature then had been 36.5 degrees. Now it was 35.9. Whether his hand could still make Yuna's warm, he didn't know. A congenital heart-valve defect. Surgery possible only in a specialized medical facility on Earth. The reason Jeongho had become a mining-ship pilot. He lifted the photo. Yuna's face was sharp and clear. Jeongho looked at his own face in the mirror. The red fleck in the iris. The oxygen-binding curve Nahyeon had spoken of. A body that, back on Earth, would deliver no oxygen to its tissues.
He had to go back to Earth. He had to sign for Yuna's surgery. The guardian's consent form. It couldn't be done remotely. A signature in person. At a distance where the communication delay ran over 6 hours, an electronic signature carried no legal force. Jeongho had to go to Earth himself. But his body no longer fit the physical laws of Earth. Jeongho laid his arm on the table and looked at the back of his hand. The color of the veins was darker than usual. Hemoglobin that would not properly bind oxygen was turning his blood black. He flipped his hand over and looked at his palm. The lines of it stood out sharply. His skin had thinned.
Jeongho went back to Nahyeon's examination room. It was night. The corridor lights were dim. The examination room door was locked. Jeongho knocked. Nahyeon opened it. She had a gown thrown over her nightclothes.
"Is there a way to turn my body back?"
Nahyeon opened the door and let Jeongho in.
"Sit."
Jeongho sat. Nahyeon switched on the monitor. Data on past mining pilots came up.
"Everyone with 3 or fewer entries was restored. There were 7 with a 4th entry, and 4 of those failed restoration."
Jeongho asked.
"And the other 3?"
"2 were partially restored. 1 was fully restored. But the one who was fully restored went back in for a 5th run and—"
Nahyeon stopped.
"What happened?"
"He never came back. Cardiac arrest inside the Domain. When they recovered him, his internal electrolyte concentration was 4 times the Earth baseline. Normal under the physical constants inside the Domain — but the moment the rescue ship pulled him outside it, his heart stopped."
Jeongho's back came off the chair. He leaned forward. He buried his face in both hands. His palms were cold. His temperature had changed too. Inside the Domain his temperature was 35.8 degrees. Outside it was supposed to return to 36.5, but Jeongho's temperature was 35.9. Caught on the Boundary. His body was wedged between two physics.
"We can attempt restoration."
Nahyeon said.
"There's a way to force a rebinding of the hemoglobin structure in the blood inside an oxygen chamber. The success rate isn't high. 40 percent."
Jeongho asked.
"And if it fails?"
"Pulmonary edema from oxygen overload. Or damage to the vessel walls."
Jeongho's hand gripped his knee.
"Yuna is waiting."
Jeongho's voice cracked. Nahyeon looked at him. Her mouth stayed shut.
Jeongho came back to his quarters and lay down on the bed. The piping on the ceiling was visible. He could hear coolant running along the pipes. Jeongho raised his left hand. He spread the palm toward the ceiling. Fluorescent light leaked between his fingers. The light hurt. His eyes couldn't adjust. Jeongho lowered his hand and closed his eyes.
The next morning, Jeongho went to the observation deck of the relay station. Through the deck's reinforced glass he could see the outside. Ice shards from the Kuiper Belt drifted by slowly. Beyond them lay the Domain. It was invisible. There was no marker on the Boundary. You couldn't tell exactly where the physical constants shifted. They shifted by degrees. Across 100,000 kilometers the minute constants changed in a continuous slide. While you were crossing, the body never noticed. Only after six weeks of work inside the Domain, once you were back out, did you realize your body had changed.
There was one other engineer on the observation deck. It was Park Eun. The engineer off the mining ship Hamdeok, which had come back before the Geongon. The skin of Park Eun's right hand was a different color from the left. The right hand was an ashen gray. From long exposure of that hand to the processing rigs inside the Domain, Park Eun said. Park Eun saw Jeongho and spoke.
"Your 5th run?"
Jeongho shook his head.
"I've got the money now."
Park Eun's gaze drifted back toward the glass.
"I'm on my 6th."
Jeongho looked at Park Eun's right hand. No veins showed beneath the ashen skin.
"The hand?"
"It doesn't come back. No feeling in it either. But inside the Domain it's normal. Live only on the inside and there's no problem at all."
Park Eun laid the right hand flat against the glass. The skin met the cold pane, but Park Eun's expression didn't change. There was nothing to feel.
"Outside it's a dead hand, inside it's a living one. Which one's the real one?"
Park Eun lowered the hand and looked at Jeongho.
"What's the reason you're going back for a 6th?"
Park Eun smiled. A smile that was only the corners of the mouth.
"It's easier on the inside. Every time I come out my body doesn't fit. I think it suits me better in there."
Jeongho looked at Park Eun's face. Ashen blotches had begun to surface on the skin too. Beside the neck, at the temple. Park Eun's body was crossing over, little by little, into a different physics.
Jeongho didn't answer. He looked past the glass. A single ice shard turned slowly, catching and throwing back the light. The light was skewed toward red. That was where the Domain came near.
Jeongho went back to his quarters and switched on the comms terminal. 5.8 hours one way to Earth. He recorded a message.
"Yuna. Dad's saved up all the money. You can have the surgery."
Jeongho stopped there. He had to say the next part. Dad is coming home. He had to say it. His mouth wouldn't open. He didn't know whether he could come home. Restorative treatment, a 40 percent success rate. Fail, and pulmonary edema. Jeongho cut the recording. He didn't delete it. He saved the half-filmed message.
Three days later, Jeongho went into the oxygen chamber. Nahyeon monitored from outside. The chamber was a cylindrical device of glass and metal. Jeongho lay down inside. The lid of the chamber closed. A seal sounded. The oxygen concentration began to climb. 21 percent, 30 percent, 45 percent. Jeongho's chest turned hot. As too much oxygen flooded the lungs, the alveoli swelled. It felt as if the spaces between his ribs were prying open. Nahyeon's voice came through the speaker.
"Heart rate 108. Blood oxygen tension rising. How is it?"
Jeongho said.
"My chest is hot."
Oxygen concentration 60 percent. Jeongho's vision went white. As oxygen oversupplied the optic nerve, the retina's signal processing warped. Jeongho shut his eyes. Even shut, it was white. It wasn't light seeping through the eyelids—the retina itself was making light. His pulse rang in his ears. Thud. Faster and faster.
"Heart rate 142. Alveolar pressure at threshold. Jeongho, tell me if there's pain."
Jeongho's hand gripped the wall of the chamber. The metal was cold. This sensation. He couldn't tell whether it was one he'd felt on Earth or one he'd felt in the Domain. Something felt like it was tearing inside his chest. Not the lungs. Somewhere deeper. It felt as if every single cell were being torn between two laws of physics. Jeongho opened his mouth. No sound came. The muscles of his throat wouldn't contract. Under the oxygen overload the muscles around his vocal cords had seized. Jeongho knocked twice on the chamber wall. The agreed signal. It meant: stop.
Nahyeon opened the chamber. She brought the oxygen down. Jeongho coughed. Blood came up with it. The coughing wouldn't stop. His back curled over. His diaphragm contracted as if in spasm. Nahyeon caught him by the back, laid him down, and wiped his mouth. On the gauze, along with the red, there was black. The black was a blood component that had mutated inside the Domain. Jeongho looked at the black on the gauze. It had come from his own body. It was a color his own body had made.
"We have to stop."
Nahyeon said.
"Keep going and the lungs won't hold."
Jeongho lay there looking at the ceiling. Through the chamber's glass he could see the fluorescent lights of the exam room. The light still hurt.
"The result?"
Nahyeon checked the monitor.
"Partial restoration. The oxygen-binding curve shifted a little. But it's still a long way to Earth's normal range."
Jeongho climbed out of the chamber and sat down on the floor of the exam room. He leaned his back against the wall. He stretched out his legs. The metal of the floor was cold. Nahyeon sat down beside him.
"One more time and it's dangerous."
Jeongho turned his head and looked at her.
"I have to get to Earth. I have to sign."
Nahyeon looked into his eyes. The red flecks in the irises.
"It's 4 months until we reach Earth. If your body chemistry can't adapt to Earth's atmosphere in that time, organ failure sets in within 48 hours of landing."
Jeongho's mouth closed. Somewhere in the corridor a set of footsteps passed by. The footsteps faded. Still leaning against the wall, Jeongho looked up at the ceiling. The ceiling of the exam room was white. The ceiling of the mining ship inside the Domain had always carried a red glow. Inside the Domain the light was easy on the eyes, the gravity was gentle, the pain was less. Here nothing fit. His body had already become a body that fit better back there. Bageun's words came back to him. It's easier on the inside.
That night Jeongho switched the comm terminal on again. He played back the recording he'd saved. He heard his own voice. 'Yuna. Daddy's saved up all the money. You can have the surgery now.' It cut off there. Jeongho listened to his own voice. The voice, too, had changed. The vibration frequency of his vocal cords had shifted. Lower and rougher than before. Whether Yuna would recognize this voice as her daddy's. Jeongho started recording again, picking up where it left off.
"Daddy might be a little late. But I'll definitely come."
His voice trembled. He stopped the recording and played it back. He listened to the trembling voice. He deleted it. He recorded again.
"Daddy's coming. Wait for me."
This time his voice didn't tremble. Jeongho pressed send. It would reach Yuna in 5.8 hours.
That same night Jeongho went to find Seokjin. The lights were on in the cargo office. Seokjin was sorting out the next shipping schedule.
"Can you send my settlement pay straight into Yuna's account?"
Seokjin looked at him.
"It's supposed to go to your own account."
"Switch it to my daughter's account. It's for her surgery."
Seokjin pulled out a form. Jeongho signed. His fingers had no strength gripping the pen. His pen pressure had weakened. The contractile force of the muscle fibers that the Domain had altered hadn't come back. Jeongho gripped the pen harder. The signature wavered. This signature was valid. Here, at least. Taking the form, Seokjin looked at the signature.
"What's wrong with your hand?"
Jeongho lowered it.
"It's cold."
Seokjin didn't ask anything more. He folded the form and slid it into the file box.
On the way back to his quarters Jeongho passed the observation deck. He tried not to stop. His feet stopped. Beyond the glass was the darkness of the Kuiper Belt. And beyond that, the Domain. Bageun had said it. On the inside, a living hand. On the outside, a dead hand. Jeongho laid his hand against the glass. The glass was cold. Sensation came from his fingertips. He could still feel it. Still.
Back in his quarters Jeongho sent Nahyeon a message. 'I'm requesting a second restoration treatment.' The reply came 3 minutes later. 'The risk of pulmonary hemorrhage is high.' Jeongho answered. 'I know.' For a while there was no reply from Nahyeon. It came 7 minutes later. 'Tomorrow, 0800.'
Jeongho lay on his bed and looked at the photo of Yuna. In the photo Yuna was smiling. He set the photo on his chest. He could feel its weight. Light paper. Yet it pressed down heavy on his chest. Jeongho looked at the ceiling. The sound of coolant ran through the piping. He raised his left hand and held it up to the fluorescent light. Light leaked through his fingers. The light still hurt. Jeongho didn't lower his hand. Tomorrow morning he would go back into the chamber. There was no telling whether his lungs would hold. If they held, he would go to Earth. There was no telling whether, over the 4-month return flight, his body would turn back to fit Earth. If it didn't, 48 hours after landing. Within those 48 hours he could sign Yuna's surgical consent form. Jeongho moved his fingers. In the light his fingers opened and closed. They still moved.
