At first the disease seemed minor, no reason for fear. Cooper, the drilling superintendent, checked some dials and smiled. “We’ve put your straw in Ganymede. Take a drink.”

Next to the pump, clear water from the moon’s underground sea flowed into the sample containers. “Testing before drinking, I want to see what’s in it first.”

“Afraid you might not like the taste?” He was joking as usual, but his voice sounded shaky. He sat on a rock to watch the samples being collected.

When the containers were full, I turned to see Cooper clutching his stomach. “What’s wrong?”

Gingerly he stood. His usually ruddy face was pale. “Stomachache.”

“We’re done for the day. Go see what the doc has for indigestion.” Indigestion, no worries.

Next morning in the lab, the base commander’s voice came over the com. “Scott, go to sick bay. They need help with lab work.”

That was the medtechs’ job. “I’m about to analyze our new samples, can’t it wait?”

“Go now.”

The sick bay door was locked—why lock a door on Ganymede? I knocked and Dr. Susan Alidou, our chief medical officer, came out and quickly closed the door behind her. She wore a mask and a yellow protective garment that formed seals with her gloves and boots.

I smiled. “Looking sharp.”

She didn’t smile back as she handed me a second outfit. “Put these on right away—mask, gloves, everything. Make sure the seals are tight.” A shout came from inside sick bay, and she ran to see what it was.

After putting on the protective stuff, I went into sick bay. The acidic smell of vomit hung in the air. Every bed was full, some of the patients were softly moaning. Susan and her two medtechs were frantically working on Cooper. His eyes were wide open and unfocused. Yesterday morning, he’d been healthy and fit. After a few minutes, Susan straightened up and pulled a sheet over his face. A cold wind of fear made my hands tremble.

Susan led me to a small lab and pointed to a tray of blood and tissue samples. “We need to identify the illness right away. Analyze those and see if the AI-1070 can find anything in its libraries.”

I did a full chemical analysis of all the samples and took pictures at a level of magnification that would show every molecule. Susan came back as the AI processed the information. Its flat mechanical voice announced, “Tests detected no sign of any known pathogen or toxin.”

Susan snorted with impatience and told the communicator to open a link to the Byrd, the ship that brought us here and still orbited above us.

In a moment, the smiling face of Dr. Simpson, their chief medical officer, filled the com screen. “Morning, Susan, how-”

Susan cut him off. “We have a medical emergency. Twenty-five cases of an unknown illness that doesn’t respond to medication, two fatalities so far, and more if we don’t solve this fast. We’ll uplink data on tissue, blood, and urine samples, and patient vital signs. Symptoms are nausea, rash mostly on the face and hands, fever, and in a few cases hallucinations. Send that information to Mars Base and Earth and tell them to figure out what it is ASAP.”

We talked to Simpson again later that day. He sounded so very calm. “Three of Earth’s best labs have all the information you gave us and are working on the problem full time. But the symptoms are so general-.”

Susan’s voice got loud. “We have ten more cases and more fatalities. My patients may not have much time.”

Simpson shook his head. “You’re in a terrible situation. It almost makes me think of the Ganymede curse.”

Susan’s eyes blazed. “Forget that garbage. Get me an answer.” She hit a switch, and the screen went black.

Simpson’s mention of the “curse” got me mad too. When planning for our base started, they sent unmanned probes to orbit Ganymede. The first three crashed on the moon’s surface. Two attempts to land personnel also crashed, with a loss of all 6 crew members. Exploring new worlds is hard and dangerous, and accidents are to be expected, but they still lead to stupid talk.

Susan lightly touched my arm. “I hate to ask this, but could you dispose of the dead?” She sighed. “We’ll have memorial services later, but immediate cremation may help in infection control.”

“Sure, I’ll take care of them both.”

“Four now.”

Each body was wrapped in a sheet, placed on a gurney, and wheeled to the plasma incinerator. I put the body in a chamber, closed the gate, and said a little prayer. Then the incinerator destroyed everything in the chamber, including the germs. That didn’t help. Five more people died the next day.

On the third day, the base commander staggered into sick bay, a sheen of perspiration on his forehead and a rash blooming on his cheeks. He shouted, “I saw them, in my quarters, small and horrible.”

Before the plague, he had been a model of calm reason. Susan came up behind him with an injection to knock him out, then she laid his unconscious body on the nearest bed. He was dead in an hour.

Susan took her frustrations out on Simpson. “I’ve tried every antibiotic, every antiviral, and every antiprionic I’ve got. No response to any of them. Fifty-six cases, ten deaths so far. We could lose every person on this base, and what are you doing?”

Simpson let out a deep breath. “We’ve got lots of people working around the clock, on board, on Mars, on Earth. It’s everyone’s highest priority—only priority. I have to go now.” The screen went dark.

Susan shook her head. “So easy when you’re orbiting above the problem.”

On the fourth day after onset, twenty people were dead and eighty were dying. One group went into the auxiliary dome that held the hydroponics bays, barricaded the connecting corridor, and sent a message that they would kill anyone who tried to join them. Their next message was a despairing voice saying, “The plague is here.” Then silence.

The morning of the seventh day, we lost both medtechs. Susan walked with those bodies to the incinerator. Later, she came to the lab and stood by the door. “A long time ago, I read a story about how a doctor in the early twentieth century treated pneumonia before antibiotics. He’d take the patient’s temperature, pat them on the shoulder, speak in a soothing tone, and listen to them talk while he hoped nature’s healing power would work. That’s what I’ve been doing, and that’s what you’ll have to do.”

“I’m a research biologist, not a doctor.”

“There’ll be no one else.”

I took a few steps toward her. Across the dark skin of her cheeks, the rash wrote its story of coming death. What was there to say but “I’m sorry.”

“I have a few more hours, and I’m going to use them.” She worked with her patients until finally she called me to come. She died the next day.

I stripped off the germ proof clothing. It hadn’t helped Susan or the medtechs. Each morning I went around the beds dispensing comfort and noting who was ready for cremation. Each afternoon Simpson told me how hard they were working to find an answer. No answer came. Soon every other living colonist was infected. There were fourteen patients, then eleven, then seven, then three, then none.

I asked Simpson why I was still alive.

“In almost every epidemic, some people don’t succumb–like the hemorrhagic fever epidemics early in the last century. Some develop the disease but recover. Others don’t get sick at all. Everyone’s immune system is different. Usually the survival percentage isn’t this small.”

“We’ll have to abandon the base. I can’t fly the shuttle by myself. Will you send one down for me?”

Simpson disappeared, and the screen showed his captain. “I’m sorry, Scott, but we can’t do that.”

“So how are you going to get me back?”

“Scott, we don’t understand this plague. You may be a carrier. I can’t risk my crew.”

“I can’t stay down here!”

“We sent down rations for 147 people. Enough of the hydroponics farm and power plant were set up to let one person survive indefinitely.”

Indefinitely! “Do you have any idea when you can bring me aboard?”

He wouldn’t look directly at the screen. “We don’t have enough fuel and supplies to remain in orbit any longer.”

“So you’re going to leave me?”

“We have no choice but to return to Mars now. Another mission will be out here in about a year—maybe then.”

“A year alone!”

“We’ll be in radio contact, and so will Mars Base. You have the AI-1070 and enough of an entertainment library to keep you occupied forever. I’m sorry, Scott.”

The communicator screen went dark. The screen that displayed the view from an external telescope showed the Byrd, a glowing orb that burned brighter as it fired its engines to escape orbit then gradually grew smaller and dimmer until it looked like just another of the cold unfeeling stars.

As the Captain said, I could talk to the AI. “1070, now what?”

“Your next scheduled activity is gravity replacement exercises.”

“What’s the point of that, if I’m stuck here forever?”

“Exercise is needed to keep your muscles from atrophying.” Its voice lacked any inflection, like the humming of an electric motor.

“Am I going to die here?”

“The answer to that question is uncertain, but your last medical exam reveals no current life-threatening condition.”

That was true. The plague hadn’t killed me. But it hadn’t made me stronger.

There wasn’t much to do. The passage to the auxiliary dome had to be opened and the five bodies there cremated in that dome’s plasma incinerator. I’d expected more bodies, because eleven people had hidden with that group. Maybe the last victims cremated the first victims. I said no prayers over the dead, no one was listening. After the last cremation, I heard a sound like running feet. A delusion? Alien monsters haunted my dreams.

The water we had drawn from Ganymede’s underground sea showed no signs of microbial life. Once that would have been a disappointment, but now it was a relief. My drill hadn’t brought up the plague. Surprisingly nothing else was in the water—it was as pure as if it had been distilled.

Simpson contacted me every day on the communicator, but we didn’t have much to talk about. On the third day, he arranged contact with two old friends of mine on Mars Base. We couldn’t really talk much. It took over a half hour for my messages to go to them and another half hour for their response to get to me. Still, seeing their faces, even if only for a minute, was great, and later they sent texts with all the gossip from my old station.

Next day the off-world communicator failed. The 1070 ran system diagnostics and found that two components had burnt out due to “unexplained overload.” It told me what replacement parts were needed and where they were in the parts inventory shed. That shed had been a picture of order, with shelves neatly stacked with boxes in a set order. Now it was a picture of chaos. Boxes were strewn all over the floor, as if someone gone mad from the plague had ripped the place apart. The box with the needed parts wasn’t there. My hands shook as I opened each box in the desperate hope that the parts had been mislabeled. They hadn’t been.

My only hope was the AI. “1070, how can the off-world communicator be fixed without those parts.”

“Those parts are required for the repair”

“Can replacements for those parts be made on Ganymede?”

“Their manufacture is complex and requires equipment found only on Earth.”

There had to be another answer. “How about rigging a substitute or a bypass?”

“Those parts are required for any transmissions of over 18,000 kilometers.” In other words, anything more distant than an orbiting ship.

“You’re supposed to be so smart, find me an alternative.”

“Receiving replacement parts from Earth is the only alternative.”

No one would be near here for a year. If then. Because my transmissions had ceased, they’d think I was dead. The next mission was planned to explore other moons, and they might not come close enough for my com.

Developing a routine helped me keep my head together. Each day started with breakfast, then gravity replacement exercises. The rows of unused equipment in the gym made me feel sad and empty.

Then I would walk around the circumference of the main dome, breathe the odorless processed air, and look out at the frozen wastes of Ganymede. The light-colored surface was full of long deep grooves that made a pattern like a spider’s web.

Often on those walks I would say something aloud, some comment on the scenery or a random thought. Talking to yourself isn’t a good sign, but I told myself it was just to hear a human voice.

Sometimes it seemed someone was watching me. People often claim they can sense if someone is watching them, glance detection they call it. But glance detection is a silly idea, like the Ganymede curse.

After lunch, reading an e-book would distract me for a while. Sometimes I’d walk through the empty streets and silent buildings of the half-built colony, but that was usually too depressing. Then came dinner, with the AI for company.

“1070, what do AI’s do for fun?”

“Request not understood.”

“Artificial intelligence has its limits, doesn’t it?”

“Do you want to access the instruction module?”

“No. What game would you like to play?”

“Request not understood.”

“I’ll pick.” An hour or two of computer games, a movie, sleep. Next day it began all over.

After about a month, the AI actually started a conversation. “You should consider the causes of the plague. Your never getting sick may be a clue. Perhaps the plague started when a pathogen you brought to Ganymede mutated. You were immune because you had antibodies to it. You served as a carrier.”

That couldn’t be. “Lab tests never found any Earth germ. The plague probably was here when we arrived. Some oxygen was on Ganymede’s surface. Microscopic life could have been here.”

“Extensive tests found no such life.”

“They had no experience with the organism. If you don’t know what you’re looking for, you won’t find it.”

“You may not find it. The pathogen wasn’t on the surface. Do you think it’s something you brought up with the drill? The plague started just after you took the first sample, didn’t it?”

“The samples were sealed.”

“Seals often aren’t perfect, or microbes could migrate up the bore hole. Wasn’t the first case on the drilling crew?”

“Tests showed no microbial life in the samples. Besides I was closer to the samples than anyone, and I didn’t get sick.”

“As you said, tests could miss an organism that humans had no experience with. Do you ever ask yourself why you didn’t get sick?”

“Constantly. I’m going to bed now.” To bed and not to sleep as questions about the plague ran through my head.

The feeling of being watched grew, as did the noises. Once I tripped over an abandoned piece of machinery and thought I heard someone laughing. My heart raced, and it was hard to breathe. Was I losing my mind?

A week later, I used the equipment in sick bay for my scheduled medical check. The AI gave me the results.

“No infection has been detected, but you are under significant stress. A major concern is the long-term effects of solitude. Prisoners kept in solitary confinement for a long time sometimes develop a syndrome characterized by hallucinations and difficulties in thinking, concentration, and memory. You have been alone now for over 5 weeks—long enough for onset of the syndrome. The high stress you were under previously increases your risk.”

The AI had changed from using few words to being voluble, which made me like it even less. “How do you treat that syndrome?”

“The only way to stop the condition from worsening is returning the prisoner to the companionship of others. The effects, however, are often irreversible.”

Madness might embrace me and never let me go. A cold sweat covered my body.

The next day’s walk took me into the auxiliary dome. A faint noise came from behind one of the buildings. And there in the shadows stood a short woman with brown eyes and raven black hair to her shoulders. Her jeans and blue cotton work shirt hung loosely on her, as if she had just lost weight. Her face was pale and had a number of scabs. I knew that face. “You’re Vera, Vera Turner.”

She took a few steps back, screamed, “Don’t come near me!”, and disappeared around a corner.

My hands shook. I might have finally found what I so desperately wanted, a companion. Searching for her would be fruitless, there were so many places to hide that she would only be found if she wanted to be. Instead I made a colony-wide announcement. “Vera, I’m Scott Jensen. Come to the communications center, please?”

Nothing but silence—had I really seen her? Maybe the AI could help. “1070, how many life forms are there in the colony?”

“The scanning system failed. The required replacement parts are not available.”

“I thought I saw a woman. Is she real?”

“The available data do not answer that question, but as noted in your physical, you are at risk for hallucinations.”

All night I wondered if I would see her again. Then on my morning walk, there she was—standing by the outer wall of the colony staring at Ganymede’s surface. She must have heard my footsteps. “Don’t come any nearer!” Her voice shook, maybe because of fear.

“How did you survive?”

“Our department head isolated us in the auxiliary dome, but we got sick anyway. I was delirious for days. Then I woke and found the others all dead. Is anyone else here?”

“We’re the only ones. Why didn’t you say something to me before?”

“You might have the plague.”

“I don’t. It’s been weeks, and I don’t have any symptoms.”

“Why are you still here?”

“The Byrd abandoned me—abandoned us. They were afraid I was a carrier.”

“Maybe you are.” In an instant she was gone.

Finding Vera seemed like a dream come true—too much like a dream come true. Back in the communications center, the questions came. Why had she and she alone recovered from the plague? The doctor said that usually some got sick but survived. Her recovery was possible, as my immunity was possible. When she found herself alone, why hadn’t she come into the main dome? Maybe because she feared the plague, as she said.

Or she could be a delusion. What was more likely, that she spent over a month in hiding, or that loneliness had taken my mind? My mouth went dry and my hands shook.

At dinner time, I made another announcement. “Vera, if the plague were going to kill us, it would have. It’s safe now. Please come to the communications center. We can eat together.”

She replied over the com. “Too dangerous.” Nothing else. I ate alone.

I tried again. “Tonight let’s watch a movie in the main hall. I could sit in the front, and you could sit in the back.”

She said nothing for a moment, then “OK.”

“Great, see you there.”

Would she come? I waited as nervous as a high school kid asking for his first date, but finally she stood in the back of the hall. “What are you watching?”

“Whatever you want.”

She shrugged. “Your pick.”

“Musicals are great, especially 21st century Bollywood. How about Bhaji’s Wedding?”


Even though, or maybe because, it was over 100 years old, the movie provided a welcome escape. At the end, she got up to go. “Scott, great movie.”

I called out to her, “Wait. Join me for breakfast tomorrow?”

She shook her head no.

“Exercises? We could use different ends of the gym?”

“Not large enough, maybe you’re a carrier.”

She disappeared out the door. She blamed me for the plague. So did the 1070. Were they right?

On my next morning walk, she appeared again. I needed more contact. “Vera, we’re the only two people out here. We should get to know each other.”

“What do you want to know?”

“Why did you come to Ganymede?”

“Like you, Earth wasn’t enough for me. That was stupid of us, wasn’t it?”

“No, don’t think that. The drive to explore is part of being human.”

“After incinerating all those bodies, you still think you belong on Ganymede?”

“What is life without risks?”

“Longer. But if you think exploring is so important, there’s no way to keep you away.” Then she was gone, as quick as a ghost.

After dinner, I got on the public address system again and asked her to join me for another movie. She appeared in the back of the hall. “You can pick what we see tonight.”

Time for another musical, this time 20th century Hollywood. For a while, the elegance of Top Hat blotted out all worries. As the last credit scrolled across the screen, Vera stayed in the back of the hall. “You really like old musicals.”

“My favorites. What are your favorites?” She fled out the door, and I was alone.

Next morning, Vera was in the same place as the day before. Her pallor was gone, and the last scabs had fallen from her face. She held up a hand to stop me about 10 feet away, but we could talk.

“Tell me about your life before Ganymede.”

Her face was expressionless. “Studied hydroponics, signed up for an adventure. How about you?”

I went on and on, telling all about my schooling, my first jobs as an Earth-bound biologist, my work at Mars base, and my eventual selection for the Ganymede colony. I finally realized I’d gone on too long. “Vera tell me more about yourself?” She shook her head and ran off again.

Even from a distance she looked so lovely. Did that prove she was a delusion? Wouldn’t the sores have left scars on a real person? There was no way to tell, because there were no other survivors to compare her to. Having some company was so much nicer than loneliness that I tried to ignore my doubts—tried and failed.

That night, I asked Vera to join me and watch Jupiter rise. I stood alone, as the planet slowly climbed into the sky above the dome. Then came her voice, soft and lilting. “Wonderful, isn’t it? The Red Spot looks like a sea of fire.”

Vera stood about 10 feet away. Jupiter’s reflected light lit her face. “You’re beautiful.”

“Thanks, I guess.” She paused for a minute. “Did you have a girlfriend back on Earth, or Mars maybe?”

“No, not in a relationship with anyone. How about you?”

“No one serious. Were you ever in a relationship?”

Telling this story still hurt. “My wife died when that rocket misfired on Mars Base.”

“Didn’t that make you want to go back to Earth?”

“No, it made me more determined than ever to stay out here.”

She shrugged her shoulders. “People are hard to understand.” Then she was gone like a dream when you awaken.

Over the next few days, we watched more movies, and we talked. She always kept me at a distance, but I began to feel affection for her, like falling in love. Was that only because there was no one else? How could I be sure my feelings were real? I wasn’t even sure she was real. Every night doubt, not sleep, filled my mind. Was she my protector from madness, or madness?

I tried the AI again. “1070, how can I tell if Vera Turner is real or a delusion?”

“Seek a third party to confirm or deny what you see.”

The AI was just full of great worthless advice. “What if no third party is available?”

“One possibility would be if she does things that no one else could do”

“She does things around the colony, mostly she maintains the hydroponics bays.”

“Could you have done those things?”

“Sure.” We were all cross trained for various jobs.

“Insufficient. Perhaps you did them and deluded yourself into thinking that she had. Or perhaps you deluded yourself into thinking they had been done. Were they dramatic changes, ones that had a large effect on you?”

“No, really for most of them there’s only her word that they happened.”

“Philosophers suggest the first thing you can be sure of is your own existence. You must exist to ask if something is a delusion. One possibility would be to create a situation where if she is a delusion, you don’t exist.”

Suddenly my throat was dry, and my voice quavered. “Please explain.”

“Put yourself in a life-threatening situation, where only she can rescue you. If you remain alive, she is real. The risks of this approach are obvious. But every explorer knows learning the truth is worth risking your life.”

I could do that. Every colonist had a space suit and dangling from its front was a cord with a safety key at the end. You could enter an airlock from outside only if someone put a safety key into a slot on the outer door or into a slot in the inner door. To ensure that a software glitch could never cause a breach in the dome, the AI could not open an airlock door.

If I went outside the dome without a key, I could return only if someone inside the dome let me in. If Vera did that, it would prove that she was real. If she didn’t, I would use up my suit’s air supply and suffocate.

If I couldn’t trust my own mind, even such an agonizing death didn’t seem so bad. The next morning, I called Vera on the com, “I’m going outside to collect surface samples. If I have a problem, I’ll call you on the suit’s com, and you can let me back in.”


The door to the airlock slowly opened. Quickly, before fear could change my mind, I detached the key from my suit, dropped it on the ground, and went into the airlock. The inner door closed, the airlock depressurized, and the outer door opened. After a few steps, the outer door automatically closed behind me. I stood alone outside the dome’s protection.

The AI’s voice came over my com. “I have detected your safety key inside the dome in front of the airlock. Are you in distress?”

What was the answer? I called Vera. “My safety key fell off my suit. Could you let me back in?”


Suddenly a small figure appeared standing inside the dome, not Vera, not human. It was 4 feet tall with a tapering body, no discernable neck, hairless and faceless. Two long arms each ended in a webbed thing with claws. Its flesh was the shiny white of a dead fish floating on the surface of a pond. “Small and horrible,” those were the commander’s words, words taken as delirium.

Its voice was high and sharp. “Vera Turner was only a hologram. But we’re real. The caverns surrounding the underground sea are our home. A home you drilled a hole in.”

“Why not contact us, find a way to live with us?”

“Two sentient races in the same solar system? We’ve never seen that work.”

“So you caused the plague.”

“After we made your probes crash, we learned human biology from the bodies. We developed a way to eliminate most of your colony, but you were left.”

“Why not just kill me?”

It waved a webbed clawed hand. The gesture looked dismissive—no doubt it was meant to be. “Unless your death looked like an accident, or suicide, the next mission would realize we were here. Ridding the system of your species requires help from our home planet, our existence must be secret until it arrives.”

“You got to the AI, didn’t you?”

“Your primitive AI was easy to reprogram. Guilt didn’t work, but your fear of madness gave us another way. Goodbye Scott.”

It was gone. As the air ran out, I turned on my suit’s voice recorder and told this story. Maybe they’ll find it and erase it. Maybe the next mission will find it and warn Earth. I’ll never know. A minute of air is left, a minute to look at the beauties of Jupiter and the red spot, the color of fire and cold as hell.

Henry McFarland is an economist and part time short story writer. He has published stories in Brain Games: Stories to Astonish, and in After Dinner Conversation, the Starship Sofa podcast, Andromeda Spaceways, and Every Day Fiction.

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