Chiral

Nobody can hear a scream in the vacuum of space, or so they say.

Yet screaming had become a nightly ritual for Shel. She would collapse onto the narrow twin bed, smother her face with her pillow, and scream. The exertion would leave her pharynx burning and her lips tasting of cheap synthetic cotton, but the tightness in her chest would feel just a little bit looser, and sleep would come just a little bit easier.

Shel awoke that morning, as she did every other morning, to the sound of birds chirping, emitting from a tiny speaker mounted above her bed. She had never actually seen a bird - the only animals on Io were the mice and insects in the biolabs - but she had always found their singing pleasant. That pleasant feeling evaporated as soon as she opened her eyes and remembered that she was no longer on Io.

She was on The Worm.

That wasn't the space station's official name, of course. It was the GalCom Experimental Communication... something something. Shel actually couldn't remember the full name anymore. The device at the station's core was one of only two machines in the solar system that could open an active wormhole, and so the station became 'The Worm.'

The cabin's overhead lights slowly brightened, in an attempt to gently and naturally awaken its inhabitant. Shel elected to rip off the bandage instead, sitting up and jamming the DAY button on the room's control console. The birds ceased their chirping and the cabin flooded with antiseptic light. Shel stood and stretched, trying to work out the kink that the cheap mattress had left in her spine, and ignoring the fact that, were her arms an inch or two longer, she could touch both walls of her claustrophobic bedchamber at the same time.

9 weeks. Only 9 weeks into her 26-week contract. Not even halfway through this nightmare.

Shel's battered back creaked and popped as she pulled on her jumpsuit and bent over to retrieve her tablet. The thin translucent rectangle woke at her touch, displaying the time: 0900. That couldn't be right. Shel had programmed the cabin to begin its day-cycle at 0600. The tablet clock had to be wrong... but it was also eerily quiet outside of her room. There should have been muffled voices, footsteps, the miscellaneous sounds of her shift-mates preparing for the day.

Shel opened her cabin door and peeked out into the Habitat Ring's main hall. It was deserted. Silent. All the other cabin doors were closed.

"Shit."

She ducked back inside, grabbed the tablet and accessed her schedule. What had she missed?

0700 - TechOps Team Breakfast (MANDATORY)

0800 - Goal-Setting Workshop (MANDATORY)

0830 - Business Improv (MANDATORY)

Right. 'Business Improv.' That line item had filled her with anxiety from the moment she spotted it last week. She had approached her team leader for an explanation, and JD had enthusiastically outlined the concept: the TechOps team would break into small groups and role-play as GalCom executives, brainstorming solutions to various corporate problems. It would give these traditionally "behind-the-scenes" employees a chance to work on their "business presence." The idea alone seemed to energize JD.

Shel just felt terror. She had grown up on Io in a habitat that housed just twenty full-timers, a quarter of whom she was related to. The others were chemists and biologists, introverted men and women who preferred silence to small talk. And if Shel ever grew tired of their presence, she could climb into a hardsuit and slip outside. Go for a walk on the sulfur snowfields and gaze up into the sky, where Jupiter and its Great Red Spot hovered perpetually.

She still had a view of Jupiter from her cabin window, but that was where the similarities began and ended. Shel was on the crew of the most advanced scientific installation in the solar system, a trillion-dollar space station packed with bleeding-edge tech, and yet, on average, she spent only two or three hours per day doing actual productive work. The remaining hours were filled with MANDATORY meetings, MANDATORY team-building exercises, MANDATORY mentoring sessions... the station had a full-time staff of over 200, and at times Shel felt as if she was required to interact with every single one of them.

Her first week, Shel had skipped the less-important sounding events - which usually had exclamation points in their names, like Martian Movie Night! - instead retreating to her cabin to trade messages with her sister, who still lived back home. Until one night, when JD dropped by to inform her that, astoundingly, movie nights were MANDATORY.

MANDATORY FUN.

That's when the screaming started. Shel wanted to scream during the meetings, and the workshops, and the small-group huddles. But she smiled during the small talk and nodded during the one-on-ones and sweated through the improvs and each night she came home and screamed her misery out into her pillow.

But today was a miracle. She'd missed three MANDATORY torture sessions by no fault of her own. A glitch or unexpected system reset had granted her three extra hours of blissful oblivion. If JD didn't believe her, all her had to do was check her cabin's error logs - the proof would surely be there.

Shel grabbed her work necessities and hurried down the hall towards the nearest lift; after a few extended strides, she felt her gait shortening. She had never been alone in the Habitat Ring before. It was huge - the outermost and largest of the station's five main Rings, it was a sprawling fractal of spotless white corridors, all of them bustling with activity during each shift change. But on this fine solar morning, Shel had the place to herself, so she slowed to a casual walk, savoring the stillness.

By the time she entered the lift, Shel felt better than she had in weeks, a feeling compounded by a literal lightening of her physical load as the chamber began to move 'inward' towards the TechOps Ring. The Worm rotated at a fixed speed to simulate gravity; the Habitat Ring - the outermost of the five rings - got around 0.2 Gs, which was comfortable for anyone raised on one of Jupiter's Galilean moons. Moving inward, each Ring experienced less gravitational force: as Shel passed the Comms Ring, she was a full kilogram lighter, and by the time she reached the TechOps ring the kink in her back had started to relax.

The lift silently slowed to a stop. In the instant before the door opened, she was seized by a peculiar notion: that a mysterious calamity had struck the station while she slept, killing or vanishing everyone on board but herself. She couldn't decide if the idea scared or thrilled her, and she didn't have to, because in the next instant the lift door opened to reveal JD, her supervisor. If he was upset by her tardiness, it wasn't showing. Regardless, Shel figured it was best to come right out with it...

"Hey, JD, you're not going to believe it, but..."

He was too excited to let her finish. "Dynamite!"

"What?"

"Real dynamite stuff this morning, Shel," JD continued, his lanky frame practically vibrating with positive energy. "That line about the GalCom quarterly margins! How the hell did you come up with that?"

Shel had absolutely no idea what he was talking about. Her boss smiled, interpreting her silence as coyness.

"I tell ya, I wish I was half as comfortable in front of a crowd as you are."

Shel was frozen in place. JD stepped around her to enter the lift.

"Anyway, let's catch up later. I have to run to Comms for a huddle."

Beyond confused, Shel awkwardly shuffled out of the elevator. As the door closed behind her, JD offered one last bit of encouragement...

"Keep up the good work, Shel!"

---

BY THE TIME Shel reached Life Support, she had worked out what must have happened. It was a case of mistaken identity - JD had mixed her up with Leda, a bubbly engineer from Callisto. Shel and Leda were the same height, and they both had curly black hair that fell to their shoulders. Shel normally wore her hair up, but would JD even notice something like that? He managed a team of 25 pale nerds wearing identical white jumpsuits. An easy mistake to make. Shel couldn't believe her good fortune. Leda must have really made an impression in that stupid improv thing. Shel owed her some commissary creds. Enough for a pastry; one of the goods ones that didn't taste like plastic.

Satisfied that her tardiness wouldn't be the source of any further drama, Shel stepped into the comforting darkness of the Life Support server room and was greeted with a barrage of curses.

"Everything okay, Aleksei?"

"Everything is fine," her brash coworker responded, without looking away from his terminal. "Apologies. Those words were not meant for you. It's this kakashin terminal, it does not keep up with me."

He continued to swear in his peculiar Earthling dialect as Shel took her seat at the terminal opposite his. Here, enveloped in the quiet thrum of a dozen server towers, was where Shel felt the most relaxed. Just her and the work. Well, and a constant barrage of Earthling swears, but Aleksei was comforting in his own way. Like Shel, he abhorred small talk and avoided personal questions. Their interactions were limited to talking shop and, when one of them went to the commissary, the customary 'hey-I'm-getting-food-do-you-want-any?' They were work colleagues and nothing more, and Shel liked it that way.

But after the tenth whispered blyad, Shel felt obligated to check in.

"What's up?"

"Oh, same-same. Just trying not to kill everyone."

This was the closet thing to a running joke that they had going. Aleksei maintained the life support systems on the Inner Rings - the minimal-gravity environments of the Lab and the Core - while Shel handled the Outer Rings. Between the two of them, they were responsible for every life on the station. Scary on paper, but the reality was less dire. Every essential process was automated, and there were failsafes on top of firewalls on top of checksums. Most days their jobs boiled down to 'keeping an eye on things.'

But Aleksei had his eye on something interesting today. Shel hovered behind him and scanned the block of code he was stressing over.

"What's that error code?" Shel asked. "I've never seen it before."

"Negative integer error." Aleksei sighed. "These are time-checks for the Core air-scrubbers. Theoretically they show the total runtime of each process." He stopped there. Not the full story. He wanted to see if Shel could figure out the rest.

"I'm guessing this is new?" she asked, playing along. "Show me last week's log."

Aleksei snorted. A pleased snort? Shel couldn't tell. But in a flash he had last week's time-checks onscreen. All the same processes, but with subtly different runtimes. Shel spotted the pattern immediately.

"Every time-check on this week's log is zero-point-six seconds faster than it was last week," Shel noted, more than a little proud of her speed. "Including the processes that were already taking less than half a second, so..."

"Bingo. Negative integer error. And there's nothing wrong with the code, which means it's a blyad hardware error."

"Either that, or you invented time travel," Shel joked.

"Ha-ha," he intoned stiffly.

"So you'll need to go to the Core to fix it?"

Aleksei nodded. Shel had been dying to visit the Core since she arrived. It was technically out of her remit, but this was her chance to change that. She thought about how best to word her request, eventually settling on...

"Can I come? Please. Please-please-please."

"Shel, you know that is not allowed."

He looked genuinely pained to crush her dreams, but that didn't make it hurt any less.

"Besides, it is no fun. You know how they all are. The Core team are bunch of pridkuri."

Assholes. Shel knew that word. It was Aleksei's favorite. He reserved it almost exclusively for his fellow Earthlings - the Core team were pridkuri, the Lab team were pridkuri. He had never called a Galilean an asshole, at least not in front of Shel. She wondered if that was its own kind of condescension, that Aleksei didn't feel strongly enough about any of the Galileans to curse them.

"JD could clear it," Shel added.

"No way am I talking to that pridkuri," Aleskei responded. Shel had forgotten that, in Aleksei's mind, JD was the biggest pridkuri on this side of the asteroid belt.

"Come on. I've been here nine weeks and I've never even been past the Lab Ring."

"Why don't you just ask him?"

"He doesn't even know my name. He just knows me as the girl who skips movie nights."

"I think he'll remember you after this morning."

That feeling struck her again, same as in the elevator. Not impending doom, but its close cousin, a doom that had already struck, without warning, and was just waiting for Shel to catch up.

"What do you mean?" Shel asked, her face hot.

"You were quite the class clown in that improv thing this morning. In a good way, I mean. Very memorable."

"That was..." Shel was going to say Leda, but there was no way Aleksei could have mixed the two of them up. She waited for a wink, a nudge, any sign that he was pulling her leg. Instead, he just stared at her blankly. Even in their low-grav environment, Shel's body felt heavy.

The silence was broken by a quiet chime from his terminal. A message popped up on Aleksei's main screen...

Physical Therapy (MANDATORY) - Starts in 15 mins

Unlike almost everything else on their daily calendars, physical therapy truly was a necessity, for Earthlings especially - they had to spend at least 60 minutes a day at the gym to keep their muscles from wasting. Aleksei dismissed the alert with a grumble and signed out of his workstation.

"Later, Shel."

"Yeah, later."

As soon as Aleksei was gone, Shel collapsed onto his chair. She wasn't confident she could make it all the way back to her own. She chewed her nails and wracked her brain for a reasonable explanation for why two people were convinced she had attended an event that she had no recollection of.

Sleepwalking? Impossible. Unless mumbled, incoherent phrases were exactly was JD was hoping for at his improv session.

A foggy childhood memory popped into Shel's head: a biologist from her Hab - she couldn't remember his name - had entered the airlock and attempted to trigger a pressure cycle without wearing a hardsuit, which would have killed him in seconds. The automated safety protocol had locked him out; still, he kept pawing uselessly at the terminal until a couple of the bigger guys - the mech team, probably - yanked him inside and tied him to the bulkhead with ratchet straps. Upon frantic questioning, the biologist kept repeating that he was 'just going for a walk.'

What had Shel's mother called it? A fugue state, brought on by stress, isolation and lack of sleep. An even-handed, logical analysis, as was her style. Shel's father had been less kind...

'Some people just aren't cut out for this life.'

Shel wondered now if that aphorism applied to her. Had she cracked?

Voices in the hall. She thought she heard her name. Shel creeped over to the door and tapped on the keypad - the aperture started to slide open, but she gently arrested its motion with her foot, leaving only a small crack through which she could peer unseen.

JD had caught Aleksei on his way to the lift. Aleksei's responses were muted, but JD's booming voice carried down the hall...

"I mean, wow, who saw that coming? She's been so quiet. If had known she could work a room like that I would have put her on the Activities Committee. We desperately need more Galilean representation."

Aleksei casually mumbled something that sounded affirmational, barely paying JD any attention. Shel felt a pang of jealousy. Aleksei was the person most like her on the whole station, but he suffered from none of her social hang-ups or bureaucratic anxieties. He coasted through every feedback meeting and group mentoring session, saying little but making his words count. Quietly confident.

"Is she around?" JD asked Alexei. "I was going to pick her brain about tomorrow's performance review rehearsals."

Aleksei tilted his head toward the server room.

Shit. Shel slapped the keypad and retreated as the door slid shut. A 'gab session' with JD was the last thing she needed right now. If she wasn't already cracked, an hour alone with him would surely shatter her psyche. She could only see one option: there was a few feet of space between the rear of the server towers and the room's back wall - it would be cramped and it would be hot, but it would have to do.

Shel slipped behind the towers just as the door slid open. She listened as her boss's padded footsteps approached her workstation.

"Shel, you in here?" he asked.

He wouldn't actually make an effort to search for her, would he? No one could be that desperate for a chat. Not wanting to find out, Shel twisted to her right, preparing to flee deeper into the shadows, into the tangled mess of copper and cable...

But a shape blocked her path.

Shel froze.

The shape leaned forward, passing into a sliver of light that cut between two server racks. It was a person. A person wearing Shel's jumpsuit. And her face.

Not a person then. A thing. A thing that had somehow stolen Shel's appearance.

The Face-Stealer put a finger to its lips, shushing Shel. It wasn't necessary. Shel was too shocked to make a sound. After a moment came the tap-tap-tap of JD's footsteps receding, followed by the server room door closing.

"Don't scream," the Face-Stealer commanded. "We need to talk. Let's sit down."

Wordlessly, Shel extricated herself from behind the server racks and sat down by her workstation. A hint of clarity worked its way into the hurricane inside her brain - whatever this thing was, it had been impersonating her all morning. It didn't make the situation any less insane, but at least there was one less question to answer.

The Face-Stealer sat across from her, in Aleksei's chair. It reached into its jumpsuit pocket and pulled out a protein bar.

"Eat something," it said. "You're light-headed from skipping breakfast."

"How do you..."

"When you were thirteen years old, you had a crush on Shawn Webster, who was fourteen, and had literally no idea you existed, even though there were only twenty people total in your Hab, which is pretty pathetic, right? Anyway, one day, you saw him sneaking a tube of marshmellow paste out of the pantry, so you got it in your head that he loved marshmellow paste, and you spent the next six months swiping a tube or two of paste from every resupply shipment. Then you boxed them all up, wrote from someone special on the lid and left it on his bunk."

The Face-Stealer paused. Its eyes were shiny. Shel's own vision was blurring. She blinked away the streaky fog.

"What happened the next morning, Shel?" The Face-Stealer asked. "When you went to the mess hall?"

"He was sharing it with..."

"...Morgan Wright," the Face-Stealer said. "He was sharing it with Morgan Wright, who was fifteen and beautiful and her skin was somehow still tan even though her and her family had arrived from Earth almost six months ago. Which, of course, was around the time Shawn had taken a liking to marshmellow paste. And so you lay in your bunk all day wondering how the hell it took you six months to notice that they liked each other, and now, with over a decade's worth of hindsight, you know that..."

"...I didn't see it because I didn't want to."

Shel wiped the tears from her cheeks. The Face-Stealer wasn't a thing. It was her. It was impossible, and yet it wasn't. So Shel asked the only question that mattered.

"How?"

The Other Shel took a deep breath.

"We don't have a lot of time, so I'll skip to the end: in thirty-six hours, everyone on this station is going to die."

Shel felt it coming: the pressure building in her chest, the muscles tensing in her neck. It was the same physiological process that her body went through every night after a long day of MANDATORY ATTENDANCE.

Shel was going to scream, and she couldn't stop it. She opened her mouth...

In a flash, Other Shel closed the distance between them and clamped a hand over her counterpart's mouth.

"Shel, come on. Why bother?" Other Shel asked. "You know what they say about screaming out here."