By the middle of the 21rst century, Humanity has pretty much kicked the land-meat habit. Historians are busy rewriting their textbooks to reflect the new narrative: how we finally realized the unsustainable burden we were placing on the Earth’s ecosystems; how we wisely chose in the nick of time to reduce that burden by eating lower in the food web.

This is only true in the most approximate sense. In fact, the decision was made by a small cadre of Vegan animal-rights activists who kept colonies of Amblyomma americanum, the Lone Star Tick, in their parents’ basements.

Amblyomma is native to Texas, the red-meatiest state of the whole fifty— which is ironic, because a bite from that tick induces a deathly allergy to red meat (more precisely to galactose-alpha-1,3-galactose, a monosaccharide found therein). With a little help from a home CRISPR kit (available from Amazon for $149.99 plus tax and shipping), the Cows Firsters managed to port that lethal trait over to bedbugs and mosquitoes and— well, pretty much any human-biting arthropod they could lay their self-righteous little hands on.

Several months and twenty thousand hyperallergic fatalities later, the red meat industry was effectively done for. Poultry enjoyed a brief renaissance in its wake— alpha-gal is not found in avian flesh— but even that came to an unfortunate end once a different group of Vegan activists played some unpleasant tricks with the avian flu virus.^[1]

By the time our story begins, fish are the only meat that most humans can eat without risking their lives. Surprisingly, people are more or less okay with this by now; even given the opportunity to gengineer their way back to red-meat consumption, most couldn’t be bothered. They’ve grown fond of the new forests springing back in the wake of all those decommissioned ranch lands, of the recovering biodiversity thriving in that reclaimed habitat. Nobody misses the millions of tonnes of heat-trapping methane all those food animals kept farting into the atmosphere year after year, either.

We also have people on Mars, a small, almost-self-sustaining colony hard at work on the early stages of rendering that planet habitable to humans. Their secret weapon is the cyanobacteria: a prokaryotic microbe which not only thrives in the naked Martian environment, but whose résumé includes the initial oxygenation of Earth’s atmosphere some 2.3 billion years ago.

There’s not yet much in the way of breathable atmosphere on Mars— it’s confined to vast diaphanous domes, blown taut by internal pressure, their ten-thousand-Hectare floors lined with cya paddies. Other, more complex species coexist in these spaces, breathing the air bestowed by the microbes: a carefully curated selection of plants and arthropods and small hardy mammals. And fish of course, swimming in meltwater recovered and desalinated from the Martian sands.

They’re doing okay, these higher creatures. They could be doing worse. But they’re no cyanobacteria, they’re not hardy enough to withstand this harsh environment entirely unscathed. Their genes sometimes get slashed to ribbons by a sleet of cosmic radiation far more intense than anything ever encountered on Earth’s surface. Even those with relatively intact genomes give birth to strange offspring; the low gravity exerts unexpected effects on the incubating young of many species. Developmental and epigenetic artefacts abound.

They’re hanging in there, of course. But to be honest, they’re also kind of a freak show. So the system still needs the occasional injection of pristine genetic material from Earth, a sort of intermittent Noah’s Ark to even out the bad stuff. Just until things stabilize, you understand.

Which is pretty much where things stand, when— buried high in the northern reaches of Vastitas Borealis— we discover the Master Bedroom of something very, very old^…

^[1]Actually, there’s one other class of red meat that doesn’t contain alpha-gal in its tissues: the primates. By the time our story opens, most of those species are already extinct or on the ropes— except for one, whose global population weighs in at 8.5 billion and continues to climb. So it’s probably worth noting that really die-hard meat aficionados do have a substantial protein pool to dip into, assuming they can resolve the relevant ethical issues.