​By the time the second batch of babies arrived on the same damned day, no one could pretend it was just a cute coincidence anymore.

The first time, late in 2104, was historic and chaotic. Four women in labor at once—Sam Sydan, Kit Tanner, Dr. Carrie Schrader herself, and Jennifer Lennox—had turned Sagan Base’s medical center into a cross between a battlefield and a birthday party. The memory of it still clung to the walls: hastily shoved-together beds, shouted orders, the metallic tang of antiseptic and sweat, and the joy that followed each new wail.

Four births. Four healthy babies. The first human beings born on Zarmina’s World, all within hours of each other.

At the time, everyone shrugged and laughed it off.

“First wave of colonists,” Fenton said as he beamed at Lucas in Sam’s arms. “They were all implanted around the same time. Of course, they’re going to pop around the same time. Give or take a week here or there, a lucky coincidence.”

And everyone had accepted it. Mostly.

But when it happened again in mid-2105, months later—different pregnancies, different couples, all due at scattered points over a several-week window—the laughter sounded a little more forced. That’s when the first sets of twins were born, all to couples with no twin births in their familial history. It became the only thing folks talked about for three weeks straight.

Carrie Schrader stood at the sink, scrubbing her hands as if the hot water and harsh orange soap could scour away questions.

Behind her, the medical center had finally gone quiet. The last of the new fathers shooed out with a promise they could come back after everyone had slept. Three fresh delivery rooms stood occupied, monitors ticking, new mothers drifting in and out of exhausted dozes while infants made soft animal sounds against their chests or in adjacent bassinets.

Three new mothers. Three sets of twins.

She dried her hands and leaned her hips against the counter, letting her shoulders slump. The clock on the wall read 03:17.

“This is nuts,” Ellie Satler muttered as she slumped into the chair beside the exam table. She wore rumpled scrubs and a paper cap askew on her curly hair. “They were due weeks apart, Carrie. I know for a fact that Pauline hadn’t even entered her eighth month of pregnancy!”

“I’m too old for this,” Carrie said, then snorted. “If this keeps up, we will need double our staff.”

Ellie huffed a tired laugh. “So, let’s list it all out. Today we admitted: Lindsey Cho, thirty-seven weeks. Amelia Ortiz, thirty-nine weeks. And Pauline Gardner, thirty-four and change. Three separate pregnancies, three different implantation dates, no shared donor DNA except the standard ARC screening. But all three went into active labor within six hours of each other.”

“On the same day,” Carrie said. “Again.”

“Again,” Ellie echoed.

Silence followed, each woman lost in her own thoughts.

Carrie pushed away from the counter and brought up the patient board on her tablet. Colored markers clustered around the bottom—pregnant patients, their estimated due dates staggered across the calendar.

“Look at this,” she said.

Ellie scooted her chair closer. Carrie pinched and spread the calendar view, highlighting dates.

“Sam, Kit, me, and Jennifer all delivered in late 2104,” Carrie murmured. “Four patients, all due within the same month, but not the same week. Every one of us went into labor on the same day.”

“I remember,” Ellie groaned. “It was a madhouse.”

“And now,” Carrie continued, “we have the second cluster. Lindsey was actually measuring ahead, Amelia behind. Pauline shouldn’t have even been close to ready. By every metric, they shouldn’t have lined up like this. But they did. Three more babies. All within a handful of hours. That’s not nothing.”

Ellie rubbed her face. “And all twins.”

Carrie swiped to another tab. The pregnancy registry filled the screen—names and numbers, weight and blood type, implantation dates and fetal counts.

“We’ve had thirty-two confirmed pregnancies since landfall,” she said. “Not counting the ones that didn’t take. Out of those? We have three sets of twins born, another eight sets of twins on the way, and one set of triplets from the ARC bank. That’s a twin rate of—”

“You’re about to tell me a number that’s going to freak me out, aren’t you?” Ellie said.

“Roughly thirty-eight percent of viable pregnancies,” Carrie said. “Back on Earth pre-ESH, the natural twin rate was closer to 1.25 to 3 percent.”

Ellie whistled softly. “And you’re sure we didn’t get some secret ARC directive labeled ‘Project Multiply’?”

Carrie shook her head. “Embryo donors are all listed. I’ve triple-checked. There’s nothing in the ARC files showing deliberate selection for multiple births. To be honest, most of these embryos should have resulted in single births. We are seeing multiples when we implant only one embryo, which is nuts. Maternal familial history directly links to most natural twin births, and none of our new mothers have a history of it.”

“So, what could it be? Ellie frowned, mystified.

Carrie hesitated, as if unwilling to share the next thought. “It sounds completely nuts, but what if something has changed in our DNA? In expectant mothers’ DNA. Maybe in how embryos implant. Maybe in how they split. I don’t know yet.”

The door chimed softly.

“Come in,” Carrie called.

Daniel Medry stepped inside, shoulders hunched with the particular tension of someone who had spent the last ten hours being alternately terrified and useless. He looked bone-deep tired, but his eyes were bright.

“How are they?” he asked.

“Everyone’s stable,” Carrie said. “Moms and babies. You can breathe.”

He exhaled, some of the tightness leaving his jaw.

“So.” He glanced at the dimmed corridors and the occupied rooms. “Six more kids who are going to argue over who gets the biggest slice of birthday cake.”

“Count yourself lucky Lucas is a November baby,” Ellie said. “This cluster’s going to be its own holiday.”

Daniel gave a faint smile, then his gaze shifted to Carrie. “You look like you swallowed a data spike.”

“Because she did,” Ellie said, levering herself to her feet. “I’m going to check on moms and babies again and then fall facedown somewhere. You two can science this to death.”

When the door slid shut behind Ellie, the room felt even smaller.

“Well?” Daniel asked quietly.

Carrie tapped the tablet, then handed it to him. “We’ve got a pattern,” she said. “And I don’t like how big it’s getting.”

He scanned the highlighted entries, lips moving silently as he did the math in his head. His frown deepened.

“Twins,” he murmured. “Triplets. Clustered birthdays. And this started after…”

“After ESH,” Carrie said. “After the virus changed the reproductive landscape. And after Azrael entered the conversation, at least for Earth.”

Daniel’s grip tightened slightly on the tablet at the asteroid’s name.

“We didn’t know about Azrael when Sam got pregnant,” he said. “Or when Kit did. Or you, or Jennifer. The council didn’t get that transmission until months later.”

“True,” Carrie said. “But Earth did. Someone back home knew an extinction-level rock was inbound when those orders for ARC embryos went out. And ESH was already wreaking havoc on fertility.”

“You’re thinking policy,” he said. “TUPG meddling with the banks.”

“I thought about it,” Carrie said. “But the logs don’t support it. And we’re seeing the same phenomenon in natural conceptions too. Lindsey’s pregnancy wasn’t ARC; it was old-fashioned, the way our ancestors did it—long nights, poor decisions, and a bottle of potato vodka.”

“Romantic,” Daniel smirked.

“My point stands,” Carrie said. “Whatever is happening, it’s not just the embryos. I’m seeing subtle shifts in hormone profiles too. Gonadotropins, progesterone, even baseline HCG curves. Nothing that would scream pathology but… the curves are steeper. Faster. As if the body, or all bodies, are leaning hard into producing more babies.”

Daniel handed the tablet back. “What are you saying?”

She met his gaze. “I think our species is trying not to die.”

They convened the discussion two days later in the small conference room off Medical, the one with the perpetually flickering light panel and the dent in the table from where someone had once dropped a diagnostic scanner.

Daniel, Sam, Carrie, Ellie, Fenton Aaronson, and Alex Smart crowded around the table. NARA glowed in the far corner, silent but attentive.

On the main screen, a notification flashed:

 

INQUIRY SENT TO EARTH AND MARS COLONY – ETA 16.7 MONTHS

 

“Let’s start with what we know,” Daniel said.

Sam, still pale but stubbornly upright, rocked Lucas’s cradle with one foot. The baby slept, oblivious to extinction-level asteroids and mitochondrial oddities.

“Thirty-two viable pregnancies since landfall,” Carrie began, swiping up a chart. “Twelve multiples, counting the current pregnancies. Two cluster days—late 2104 and mid-2015—with four and six births, respectively. All of this after ESH has already decimated fertility back home.”

“And we’re not an isolated case,” Fenton added. “We’ve got pre-Impact data in the transmission packets from New Athens and a half-dozen other major population centers mentioning a rise in multiples even as the miscarriage rate has jumped precipitously right alongside it. Janelle Brooks’ team was studying this right until Impact. The transmission packets spelled it out, but we were overwhelmed by all the other information flooding us from Earth and couldn’t keep up. It looks like no one read the files until last week after Alex ran a search string for multiple births. The Brooks’ team logged a large uptick in them, even as overall successful pregnancies plummeted.”

Alex leaned back, folding his arms. “So… fewer pregnancies, higher fetal deaths, but more babies per pregnancy.”

“That’s the trend,” Carrie said.

“Could it be the virus itself?” Fenton asked. “ESH was a population control measure in swine, right? Highly teratogenic at that. Someone could have built a backdoor into it. A compensatory mechanism that kicks in when population density drops below a certain threshold.”

Sam raised an eyebrow. “So, the same people who unleashed the virus built a ‘just kidding, let’s have twins’ subroutine into it? That seems… optimistic.”

Fenton grimaced. “I said ‘could.’ Not ‘likely.’”

“Environmental?” Alex suggested. “Radiation from the red dwarf? Gravity stress? Something in the food chain?”

“We’re not seeing enough of a divergence from pre-Impact Mars and Lunar data to pin it solely on Zarmina’s environment,” Ellie said. “If anything, some of the earlier Mars transmissions hint at similar reproductive weirdness, the evacuees have already reproduced at Huygens twice, and get this, multiple births on the same days and three instances of twins.”

“Right,” Daniel said. “Antonia Nix and Leonard Snelling filed two reports mentioning unexpected multiples in the AB-positive cohort, remember?”

Fenton nodded. “She attributed it to AB-linked nanite interactions and viral remnants. But in hindsight…”

“…it might be part of a bigger pattern,” Carrie finished.

Silence fell for a moment, heavy with unasked questions.

“Okay,” Alex said eventually. “Let’s assume there is a pattern. Fertility collapses thanks to ESH, mortality spikes with the virus and then with Azrael, and suddenly every successful pregnancy is more likely to be carrying two or three passengers, and those deliveries keep lining up on the same days. What’s the mechanism?”

“Biological,” Fenton said immediately.

“Or narrative,” Sam murmured.

They all looked at her.

She shrugged one shoulder, still rocking the cradle. “Look, we’re human. We like stories. If you tell people, ‘Random chance plus skewed sampling plus viral mutation equals weird baby clusters,’ they’ll nod and go back to work. If you tell them, ‘On some deep, buried level, our DNA knows we’re on the brink and is doing everything it can to keep us alive,’ they might… actually believe we have a future. And right now? We need that.”

“That isn’t science,” Alex said.

“It’s also not not science,” Carrie replied. “We’re talking about emergent behavior in a system under unprecedented stress. We don’t know how many adaptive levers evolution has tucked down at the mitochondrial level. Most of the time we see it in hindsight.”

Fenton tapped his fingers on the table. “There is another angle,” he said. “In the reports, Janelle flagged an unknown protein fragment in post-ESH reproductive blood panels. She labeled it ‘MT-ΔX’—mitochondrial delta-unknown—because it only showed up in women who conceived after infection or exposure. Completely absent in pre-ESH baselines.”

“Let me guess,” Alex said. “No one had time to follow up before the sky fell.”

Fenton grimaced. “Pretty much. They were too busy triaging and building redoubts.”

Carrie turned to the screen. “NARA, search local transmission packets for ‘MT-ΔX’ plus ‘Brooks’ and ‘Aaronson.’”

“Searching,” NARA replied.

A moment later, lines of compressed text and scan thumbnails filled the wall.

“Found four relevant documents,” NARA said. “Two preliminary conference abstracts from New Athens, one internal CDC memo, and one joint draft by Brooks, Janelle and Aaronson, Julie.”

Carrie’s heart kicked once at the second name. “Put the memo up,” she said.

The text expanded, clean and clinical. Even half a galaxy away, the language of medicine remained the same.

Preliminary findings suggest the emergence of a novel mitochondrial-associated factor (provisionally designated MT-ΔX) in post-EcoNu/ESH reproductive cohorts. MT-ΔX appears correlated with increased ovulation of multiple oocytes per cycle and reduced spontaneous embryo resorption in early gestation. Hypothesis: MT-ΔX functions as an adaptive response to acute population bottleneck—i.e., a species-level attempt to increase offspring yield per successful conception.

Carrie’s throat went dry. “There it is,” she whispered.

“‘Species-level attempt,’” Sam repeated softly. “They actually wrote it down.”

Daniel exhaled slowly. “So, it’s not just us.”

“Not just us,” Fenton agreed. “Earth saw it too. Maybe Mars. We just… didn’t have a name for it yet.”

Alex squinted at the memo. “This could still be pure emergent biochemistry,” he argued. “Virus smacks the reproductive system around, mitochondria compensate in weird ways, the ones with MT-whatever have more surviving offspring, and bam, there’s your selective pressure. No intent. No ‘trying.’ Just math.”

“Of course it is math,” Carrie said. “Evolution always is. But humans are linear thinkers. We translate math into meaning. That’s how we stay sane.”

Daniel rubbed at the scar along his ribs. The skin still felt tight, sensitive. “Back on Calypso,” he said, “when everything went to hell on the Cryo deck, I told myself I was just… reacting. One second to the next. But when I look back, it’s like watching someone else with a script I didn’t know I had. ‘You will not let them die here. You’re going to do whatever it takes.”

He looked up, meeting each of their eyes.

“Maybe that’s all this is,” he said. “A script we didn’t know we had. Written in proteins and mitochondrial membranes instead of words.”

Sam reached over and squeezed his hand.

Carrie nodded slowly. “We can argue semantics all day. ‘Attempt’ versus ‘effect.’ But the core is the same: under catastrophic threat, human biology is acting as if it knows we’re in trouble. Fewer conceptions, more babies per conception. Birthdays cluster together like there is safety in numbers.”

“Clustering,” Ellie whispered. She had slipped back in unnoticed, dark circles like bruises under her eyes. “You know, there’s literature on that in other species. Predator-heavy environments. Some herds time births so that most offspring arrive within the same narrow window. Overwhelm the predators. Some get eaten. Enough don’t.”

“Predators,” Alex muttered. “We’ve upgraded from wolves to Extinction Level Event.”

“Along with a designer virus,” Fenton said grimly.

“And yet.” Sam gestured around them—at Lucas’s cradle, at the wall that listed each new birth. “Here we are.”

“What do we do with this?” Daniel asked. “As a colony? As a story we tell ourselves?”

Carrie rested her elbows on the table and laced her fingers together. “First, we confirm,” she said. “We screen for MT-ΔX here. Full panel on every pregnant patient, and a retrospective pull on stored blood samples near implantation. We send a formal query back to what’s left of Earth and forward to Mars: ‘Are you seeing the same factor, and what outcomes are you tracking?’”

“Add twins to the subject line,” Ellie said. “They’ll open it faster.”

“Second,” Carrie continued, “we adjust planning. If birth clusters keep happening, we need staffing and resources ready. I’m not going through another night like this with a skeleton crew and a prayer.”

“I’ll push for more cross-training,” Daniel said. “We’ll get additional med techs out of the general labor pool, at least enough to handle another multiple-birth/multiple patient situation.”

“And third,” Carrie said, “we decide what we tell people.”

The room grew quieter.

“The truth,” Alex said. “Obviously.”

“Truth, yes,” Carrie said. “But also framing. There are plenty of traumatized people here. Most have learned that the ESH virus wiped out their families. They just saw Azrael shatter their home planet from sixteen and a half months in the past.” “They know, logically, that we might be it. Or the biggest piece of ‘it’ left. If we walk into the Commons and say, ‘Hey, we found a weird protein that might be a glitch or might be evolution panicking, shrug emoji,’ that doesn’t help anyone.”

Daniel grimaced. “What do you think we should say?”

Carrie looked at Sam.

“We say,” Sam began slowly, “that our bodies haven’t given up on us. That Lucas, Lindsey’s kids, Kit’s twins, all the little ones still to come aren’t accidents. They’re… our species pulling every lever it has left to keep going. That even when we were busy screwing up the planet and building designer plagues, something quiet and stubborn in our blood refused to quit.”

She met each gaze in turn, voice steady.

“We say we built a lot of instruments of our own destruction,” she said. “But somewhere deep down, we also built this.”

No one said anything for a moment.

Finally, Alex muttered, “For a bunch of meat-robots running evolutionary code, we sure are sentimental.”

“Shut up, Smart,” Ellie said without heat. “Let the woman have her hopeful monologue.”

“NARA, draft a transmission to Earth summarizing observed multiple birth patterns and referencing MT-ΔX,” Daniel said.

A moment later the draft scrolled on their tablets. “Are there any changes before the transmission is sent?” NARA asked.

“Yes,” Daniel said. “Flag it priority. And copy Mars.”

“Understood,” NARA replied. “Estimated arrival time to Earth: sixteen point seven months. To Mars: fourteen point two.”

“So long as nobody sneezes on the relays,” Alex said.

“Do not sneeze on the relays,” NARA responded dutifully.

Someone actually laughed at that, thin but real.

The reply from Earth didn’t arrive until well into 2107.

By then, two more clusters had occurred on Zarmina’s World—one in early 2106, another in the autumn of 2106. Neither were as dramatic as the first four-birth spectacle, but both fell into the same eerie pattern. Women with due dates scattered across weeks went into labor within a day of each other, as if some inaudible bell had rung.

The nursery at Sagan Base grew loud.

Lucas toddled underfoot, perpetually sticky and inexplicably fast, while a small horde of children born within months of him turned every common space into a minefield of toys. Kit’s twins, Deeks and Kethryn, were already conspiring in that wordless way twins did, communicating entire plans with a glance. Lindsey’s daughters shouted nonsense songs at the top of their lungs.

Birthdays became community events. There were too many of them sharing birthdays to do anything else. It became far easier to celebrate them as a group.

And always, in the back of Carrie’s mind, the MT-ΔX assays piled up. The pattern held. Every woman who had conceived post-ESH, whether here, on Earth, or Mars, carried the protein fragment. And this was despite their lack of exposure to the ESH virus. Somehow across trillions of miles, the colonists’ bodies knew on a mitochondrial level that their species was in trouble and reacted. It burned bright in mitochondrial panels, a ghost signature overlaying ancient machinery.

When the Earth packet finally dropped into the buffer, NARA pinged Carrie directly. She abandoned her half-finished charting, wiping tired eyes as she hurried to the comms room.

Daniel was already there, leaning over Alex’s shoulder as the younger man decrypted the bundle.

“Got something flagged from New Athens Medical Continuity Council,” Alex said. “Survived Azrael’s temper tantrum, apparently.”

He pushed the message to the big screen.

 

TRANSMISSION PACKET

ECM TO ZWC

/BEGIN TRANSMISSION

Acknowledgment of receipt: MT-ΔX / multiple birth inquiry.

Summary findings, pre- and post-Impact:
Significant increase in multiple gestations among post-ESH conception cohorts (up to 5–7× baseline in some regions).
Emergence of novel mitochondrial-associated factor MT-ΔX in reproductively active individuals post-infection/exposure.
Correlative models strongly suggest MT-ΔX functions to increase viable offspring per successful conception via promotion of multiple oocyte release and suppression of early embryonic resorption.
Observed across genetically diverse populations and in isolated survivor communities, including dome-habitats and redoubt clusters.

Interpretive note (non-technical): Our species appears to be “leaning into” survival at the cellular level. We concur with your working hypothesis that this constitutes an adaptive response to a perceived extinction-level threat. recommend you continue tracking birth clustering patterns and multiples in your population.

/END TRANSMISSION

 

No one spoke for a long beat.

“So,” Alex said eventually. “Earth is on board the ‘our DNA knows we’re screwed’ train.”

“‘Adaptive response to an extinction-level threat,’” Fenton quoted. “That’s as close as you’re going to get to a poetic flourish from a burnt-out taskforce.”

Carrie felt something expand in her chest—equal parts awe and sorrow. “Continuation Factor,” she murmured. “I like that better than MT-ΔX.”

Daniel nodded slowly. “It’s everywhere,” he said. “New Athens. The domes. The redoubts. Mars. Here.”

“Everywhere humanity is still breathing,” Sam added from the doorway. Lucas barreled past her legs, making a beeline for Daniel. He scooped the boy up and swung him onto his hip with automatic ease.

“Apparently,” Fenton said, “our mitochondria took one look at ESH and Azrael and said, ‘Absolutely not.’”

Alex tipped his chair back; hands laced behind his head. “I have to say,” he said reluctantly. “As emergent hacks go, this is… kind of beautiful.”

Months later, on a cool twilight evening along the terminator, Daniel stood at the edge of the central green watching the children play.

The air smelled of damp soil and something faintly spicy from the imported Earth herbs Kit had coaxed into the alien soil. Lights from the printed houses cast warm pools on the path. The sky was a dusky violet, the red dwarf sun a low glow on the horizon behind him, its weaker light painting everything in long shadows.

Lucas shrieked with laughter as he chased one of Kit’s twins around a planter, tiny boots thudding on compacted earth. Nearby, two girls played a clapping game with a little boy the same age, but half a head taller. A baby carrier rocked gently where someone had set it down, its occupant observing the chaos with solemn dark eyes.

Daniel took them in, one by one. He knew the stories behind most of them. The grief that had preceded their conceptions. The quiet, stubborn hope that had carried their parents through the end of their home world and their colonization of this one.

Carrie joined him, arms folded against the chill. “We’ve got three more due within the next six weeks,” she said. “Two singletons, one set of twins. I’ve got bets with the new trainees in Medical on whether they’ll decide to make it another shared birthday.”

“You gambling on children’s birth dates now, Doc?” he asked.

“I work damned hard, so I figure I get to have at least one vice,” she said dryly. “Besides, we’re building the datasets as we go. Might as well have a little fun.”

He watched Lucas trip, roll, and pop back up, unbothered. Zarmina’s higher gravity had turned all of their kids into dense little tanks.

“You buy the official line?” he asked quietly. “Continuation Factor. Species-level adaptation. Our DNA pulling out all the stops to keep us going.”

Carrie considered.

“I certainly buy the data,” she said. “MT-ΔX is real. The multiple birth rates are real as well. The clustering is real. Those are facts.” She nodded toward the kids. “What we call it, the story we layer on top—that’s culture. But culture matters. Stories matter. They decide whether people give up or keep going.”

Daniel nodded slowly. “When we first got Chen’s message about Azrael,” he said, “I thought that was it. We’d run the last program. Virus, asteroid, end credits.”

He watched Lucas tackle one of the girls. They went down in a tangle of limbs, then came up laughing.

“But then the kids started coming,” he continued. “One after another. Some part of me kept thinking, this isn’t what extinction looks like.”

Carrie smiled, the fine lines at the corners of her eyes deepening. “No,” she said. “This is what refusal looks like.”

“Refusal,” he echoed. “I like that.”

Behind them, a chime sounded from someone’s wrist comm. A murmur went through the adults scattered around the green.

Carrie checked her own comm and raised an eyebrow. “Speak of the devils,” she said. “Lindsey’s just reported her water broke. And Amelia Ortiz is having contractions again, a month early. Jennifer’s on her way in to keep them company.”

Daniel blinked. “All today?”

Carrie’s grin turned wry. “Looks like the Continuation Factor’s ringing the bell again.”

He looked once more at the children racing in the twilight, then up at the unfamiliar stars overhead. Somewhere, far behind them in space and time, Earth still smoldered under a shroud of ash, its remaining pockets of humanity huddled around dwindling resources. Mars spun on, red and stubborn. Here on Zarmina’s World, a handful of humans clung to hope in an alien world.

“No rest for the wicked,” Carrie said, sighed and headed toward Medical, gearing up to welcome the next birth cohort into the world.

He nodded and then raised his voice. “Lucas! Time to get ourselves back home.”

Lucas barreled toward him without hesitation, leaping into the air the last two feet, trusting that his father would catch him. Daniel scooped him up and held him close.

As he headed for home, the comm buzzed with updates. And Daniel found that the tight knot of dread he had carried since the ESH outbreak, since Calypso, since the Azrael transmission, had shifted. Not vanished; perhaps it never would. But wrapped around it now was something else.

A quiet, stubborn conviction that as long as there were humans left, as long as some hidden enzyme in their blood kept whispering more, try again, don’t quit, humanity had not yet agreed to disappear.

Maybe it was only biochemistry. Maybe it was something you could label and quantify and chart on a graph.

But to the colonists of Zarmina’s World, it felt like this:

Underneath everything they had seen or left behind, beneath the viruses and the asteroid they hadn’t seen coming, their own cells had voted against extinction.

And for now, that was enough.