Chapter no 14

Project Hail Mary

‌Another day, another staﬀ meeting. Who would have thought saving the world could be so boring?‌

The science team sat around the meeting-room table. Me, Dimitri, and Lokken. For all her talk about cutting out bureaucracy, Stratt ended up with a bunch of de facto department heads and daily staﬀ meetings.

Sometimes, the stuﬀ we all hate ends up being the only way to do things.

Stratt sat at the head of the table, of course. And next to her was a man I’d never seen before.

“Everyone,” Stratt said. “I want you to meet Dr. François Leclerc.” The Frenchman to her left waved halfheartedly. “Hello.”

“Leclerc is a world-renowned climatologist from Paris. I’ve put him in charge of tracking, understanding, and—if possible—ameliorating the climate eﬀects of Astrophage.”

“Oh, is that all?” I said.

Leclerc smiled, but it faded quickly.

“So, Dr. Leclerc,” Stratt said. “We’ve been getting a lot of conﬂicting reports on exactly what to expect from the reduction of solar energy. It’s hard to ﬁnd any two climatologists who agree.”

He shrugged. “It’s hard to ﬁnd two climatologists who agree on the color of an orange. It is, unfortunately, an inexact ﬁeld. There is a lot of uncertainty and—if I’m being honest—a lot of guesswork. Climate science is in its infancy.”

“You’re not giving yourself enough credit. Out of all the experts, you’re the only one I could ﬁnd whose climate-prediction models were proven true over and over again for the last twenty years.”

He nodded.

She gestured to a disorderly mass of papers on the meeting table. “I’ve been sent every kind of prediction from minor crop failures to global biosphere collapse. I want to hear what you have to say. You’ve seen the predicted solar-output numbers. What’s your take?”

“Disaster, of course,” he said. “We’re looking at extinction of many species, complete upheaval of biomes all over the world, major changes in weather patterns—”

“Humans,” Stratt said. “I want to know how this aﬀects humans, and when. I don’t care about the mating grounds of the three-anused mud sloth or any other random biome.”

“We’re part of the ecology, Ms. Stratt. We’re not outside it. The plants we eat, the animals we ranch, the air we breathe—it’s all part of the tapestry. It’s all connected. As the biomes collapse, it’ll have a direct impact on humanity.”

“Okay, then: numbers,” Stratt said. “I want numbers. Tangible things, not vague predictions.”

He scowled at her. “Okay. Nineteen years.” “Nineteen years?”

“You wanted a number,” he said. “There’s a number. Nineteen years.” “Okay, what’s nineteen years?”

“That’s my estimate for when half the people currently alive will be dead.

Nineteen years from now.”

The silence that followed was unlike anything I’d ever experienced. Even Stratt was taken aback. Lokken and I looked to each other. I don’t know why but we did. Dimitri’s mouth fell agape.

“Half?” Stratt said. “Three point ﬁve billion people? Dead?” “Yes,” he said. “Is that tangible enough for you?”

“How can you possibly know that?” she said.

He pursed his lips. “And just like that another climate denier is born. See how easy it is? All I have to do is tell you something you don’t want to hear.”

“Don’t patronize me, Dr. Leclerc. Just answer my questions.”

He crossed his arms. “We’re already seeing major weather-pattern disruptions.”

Lokken cleared her throat. “I heard there were tornadoes in Europe?” “Yes,” he said. “And they’re happening more and more often. European

languages didn’t even have a word for tornado until Spanish conquistadors

saw them in North America. Now they’re happening in Italy, Spain, and Greece.”

He tilted his head. “Partially, it’s because of shifting weather patterns. And partially it’s because some lunatic decided to pave the Sahara Desert with black rectangles. As if a massive disruption of heat distribution near the Mediterranean Sea wouldn’t have any eﬀects.”

Stratt rolled her eyes. “I knew there’d be weather eﬀects. We just don’t have any other choice.”

He pressed on. “Your abuse of the Sahara aside, we’re seeing bizarre phenomena all over the world. The cyclone season is oﬀ by two months. It snowed in Vietnam last week. The jet stream is a convoluted mess changing day by day. Arctic air is being brought to places it’s never been before, and tropical air is going well north and south. It’s a maelstrom.”

“Get back to the three and a half billion dead people,” Stratt said.

“Sure,” he said. “The math of famine is actually pretty easy. Take all the calories the world creates with farming and agriculture per day, and divide by about ﬁfteen hundred. The human population cannot be greater than that number. Not for long, anyway.”

He ﬁddled with a pen on the table. “I’ve run the best models I have. Crops are going to fail. The global staple crops are wheat, barley, millet, potatoes, soy, and most important: rice. All of them are pretty sensitive about temperature ranges. If your rice paddy freezes over, the rice dies. If your potato farm ﬂoods, the potatoes die. And if your wheat farm experiences ten times normal humidity, it gets fungal parasites and dies.”

He looked at Stratt again. “If only we had a stable supply of three-anused mud sloths, maybe we’d survive.”

Stratt pinched her chin. “Nineteen years isn’t enough time. It’ll take thirteen years for the Hail Mary to get to Tau Ceti, and another thirteen for any results or data to come back. We need at least twenty-six years. Twenty- seven would be better.”

He looked at her as if she’d grown another head. “What are you saying? This isn’t some optional outcome. This is happening. And there’s nothing we can do about it.”

“Nonsense,” she said. “Humanity has been accidentally causing global warming for a century. Let’s see what we can do when we really set our minds to it.”

He drew back. “What? Are you kidding?”

“A nice blanket of greenhouse gases would buy us some time, right? It would insulate Earth like a parka and make the energy we are getting last longer. Am I wrong?”

“Wha—” he stammered. “You aren’t wrong, but the scale…and the morality of deliberately causing greenhouse-gas emissions…”

“I don’t care about morality,” Stratt said. “She really doesn’t,” I said.

“I care about saving humanity. So get me some greenhouse eﬀect. You’re a climatologist. Come up with something to make us last at least twenty-seven years. I’m not willing to lose half of humanity.”

Leclerc gulped.

She made a shooing motion. “Get to work!”

—

It takes three hours and the addition of ﬁfty words to our shared vocabulary, but I am ﬁnally able to explain radiation—and its eﬀects on biology—to Rocky.

“Thank,” he says in unusually low tones. Sad tones. “Now I know how my friends died.”

“Bad bad bad,” I say. “Yes,” he chimes.

During the conversation, I learned the Blip-A has no radiation protection at all. And I know why Eridians never discovered radiation. It took a while to

assemble all of this information, but here is what I know:

The Eridian homeworld is the ﬁrst planet in the 40 Eridani system. Humans actually spotted it a while ago, obviously not knowing there was a whole civilization there. The catalog name for it is “40 Eridani A b.” That’s a mouthful. The planet’s actual name, from the Eridians, is a collection of chords like any other Eridian word. So I’ll just call it “Erid.”

Erid is extremely close to its star—about one-ﬁfth as far as Earth is from our sun. Their “year” is a little over forty-two Earth days long.

It’s what we call a “super-Earth,” weighing in at eight and a half times Earth’s mass. It’s about twice Earth’s diameter, and a little over double the surface gravity. Also, it spins very fast. Absurdly fast. Their day is only 5.1 hours long.

That’s when things started to fall into place.

Planets get magnetic ﬁelds if the conditions are right. You have to have a molten-iron core, you have to be in the magnetic ﬁeld of a star, and you have to be spinning. If all three of these things are true, you get a magnetic ﬁeld. Earth has one—that’s why compasses work.

Erid has all of those features on steroids. They are larger than Earth, with a larger iron core. They are close to their star, so they have a much stronger magnetic ﬁeld powering their own ﬁeld, and they spin extremely fast. All told, Erid’s magnetic ﬁeld is at least twenty-ﬁve times as strong as Earth’s.

Plus, their atmosphere is extremely thick. Twenty-nine times as thick.

You know what strong magnetic ﬁelds and thick atmospheres are really good at? Radiation protection.

All life on Earth evolved to deal with radiation. Our DNA has error- correction built in because we’re constantly bombarded with radiation from the sun and from space in general. Our magnetic ﬁeld and atmosphere protect us somewhat, but not 100 percent.

For Erid, it’s 100 percent. Radiation just doesn’t get to the ground. Light doesn’t even get to the ground—that’s why they never evolved eyes. The surface is pitch-dark. How does a biosphere exist in total darkness? I haven’t asked Rocky how that works yet, but there is plenty of life deep in Earth’s oceans where the sun doesn’t shine. So it’s deﬁnitely doable.

Eridians are extremely susceptible to radiation, and they never even knew it existed.

The next conversation took another hour and added a few dozen more words to the vocabulary.

Eridians invented space travel quite a while ago. And with their unparalleled materials technology (xenonite) they actually made a space elevator. Basically a cable leading from Erid’s equator up to the synchronous orbit with a counterweight. They literally take elevators to get into orbit. We could do that on Earth if we knew how to make xenonite.

Thing is, they never left orbit. There was no reason to. Erid has no moon. Planets that close to a star rarely do. The gravitation tidal forces tend to rip would-be moons out of orbit. Rocky and his crew were the ﬁrst Eridians to leave orbit at all.

So they never found out that Erid’s magnetic ﬁeld, which extends well beyond its synchronous orbit, had been protecting them all that time.

One mystery remained.

“Why did I not die, question?” Rocky asks.

“I don’t know,” I say. “What’s diﬀerent? What do you do that the rest of your crew didn’t do?”

“I ﬁx things. My job is to repair broken things, create needed things, and keep engines running.”

Sounds like an engineer to me. “Where were you most of the time?” “I have room in ship. Workshop.”

I’m getting an idea. “Where is workshop?”

“In back of ship near engines.”

That’s a sensible place to put your ship’s engineer. Near the engines, where things are most likely to need maintenance or repairs.

“Where does your ship store Astrophage fuel?”

He waves a hand generally around the rear of the ship. “Many many containers of Astrophage. All in back of ship. Close to engines. Easy to refuel.”

And there’s the answer.

I sigh. He’s not going to like this. The solution was so simple. They just didn’t know it. They didn’t even know the problem until it was too late.

“Astrophage stops radiation,” I say. “You were surrounded by Astrophage most of the time. Your crewmates weren’t. So the radiation got to them.”

He doesn’t respond. He needs a moment to let that sink in. “Understand,” he says in low notes. “Thank. I now know why I not die.”

I try to imagine the desperation of his people. With a space program far

behind Earth’s, no knowledge of what’s outside, and still making an interstellar ship in a bid to save their race.

No diﬀerent from my situation, I guess. I just have a little more technology.

“Radiation is here too,” I say. “Stay in your workshop as much as you can.”

“Yes.”

“Bring Astrophage to this tunnel and put it on the wall.” “Yes. You do same.”

“I don’t need to.”

“Why not, question?”

Because it doesn’t matter if I get cancer. I’m going to die here anyway. But I don’t want to explain that I’m on a suicide mission right now. The conversation’s been pretty heavy already. So I’ll tell him a half-truth.

“Earth’s atmosphere is thin and our magnetic ﬁeld is weak. Radiation gets to the surface. So Earth life evolved to survive radiation.”

“Understand,” he says.

He continues working on his repairs while I ﬂoat in the tunnel. A random thought occurs to me. “Hey, I have a question.”

“Ask.”

“Why is Eridian science and human science so similar? Billions of years, but almost the same progress.”

It’s been bugging me for a while. Humans and Eridians evolved separately in separate star systems. We had no contact with each other until now. So why is it that we have almost identical technology? I mean, Eridians are a little behind us in space technology, but not a ton. Why aren’t they in their stone age? Or some superfuturistic age that makes modern Earth look antiquated?

“Has to be, or you and I would not meet,” Rocky says. “If planet has less science, it no can make spaceship. If planet has more science it can understand

and destroy Astrophage without leaving their system. Eridian and human science both in special range: Can make ship, but can’t solve Astrophage problem.”

Huh. I hadn’t thought of that. But it’s obvious now that Rocky says it. If this happened when Earth was in the Stone Age, we would have just died. And if it happened a thousand years from now, we’d probably work out how to deal with Astrophage without breaking a sweat. There is a fairly narrow band of technological advancement that would cause a species to send a ship to Tau Ceti to look for answers. Eridians and humans both fall into that band.

“Understand. Good observation.” But it nags at me. “Still unusual. Humans and Eridians are close in space. Earth and Erid are only sixteen light-years apart. The galaxy is one hundred thousand light-years wide! Life must be rare. But we are so close together.”

“Possible we are family.” We’re related? How could—

“Oh! You mean…whoa!” I have to wrap my head around this one. “I not certain. Theory.”

“It’s a darn good theory!” I say.

The panspermia theory. I argued with Lokken about it all the time.

Earth life and Astrophage are way too similar for it to be coincidence. I suspected Earth was “seeded” by some ancestor of Astrophage. Some interstellar progenitor species that infected my planet. But it never occurred to me until now that the same thing might have happened to Erid.

There could be life all over the place! Anywhere it can possibly evolve from an Astrophage-like ancestor into the cells I have today. I don’t know what this “pre-Astrophage” organism would be like, but Astrophage is pretty darn tough. So any planet that can possibly support life of any kind would be likely to get it.

Rocky might be a long-lost relative. Very long. The trees outside my house back home are closer relatives to me than Rocky. But still.

Wow.

“Very good theory!” I say again.

“Thank,” Rocky says. I guess he’d worked that all out a while ago. But I still had to let it sink in.

—

For once, an aircraft carrier was the perfect place to be.

The Chinese Navy didn’t even question Stratt’s orders anymore. The higher-ups got sick of approving every action and ﬁnally just issued a general order to do whatever she said as long as it didn’t involve ﬁring weapons.

We anchored oﬀ the coast of western Antarctica in the dead of night. The coastline sat in the extreme distance, visible only by moonlight. The entire continent had been evacuated of humans. Probably an overreaction—the Amundsen–Scott South Pole Station was 1,500 kilometers away. The people there would have been just ﬁne. Still, no reason to take chances.

It was the largest naval exclusion zone in history. So big, even the U.S. Navy had to stretch itself thin to make sure no commercial ships entered the area.

Stratt spoke into a walkie-talkie. “Destroyer One, conﬁrm observation status.”

“Ready,” came an American accent. “Destroyer Two, conﬁrm observation status.” “Ready,” came a diﬀerent American’s voice.

The scientiﬁc team stood together on the carrier’s ﬂight deck, staring toward land. Dimitri and Lokken hung back away from the edge. Redell was oﬀ in Africa running the blackpanel farm.

And of course Stratt stood slightly ahead of everyone else.

Leclerc looked for all the world like a man being led to the gallows. “We’re almost ready,” he said with a sigh.

Stratt clicked on her walkie-talkie again. “Submarine One, conﬁrm observation status.”

“Ready,” came the response.

Leclerc checked his tablet. “Three minutes…mark.”

“All ships: We are at Condition Yellow,” Stratt said into her radio. “Repeat: Condition Yellow. Submarine Two, conﬁrm observation status.”

“Ready.”

I stood next to Leclerc. “This is unbelievable,” I said.

He shook his head. “I wish to God this wasn’t on my shoulders.” He ﬁddled with his tablet. “You know, Dr. Grace, I have spent my entire life as an unapologetic hippie. From my childhood in Lyon to my university days in Paris. I am a tree-hugging antiwar throwback to a bygone era of protest politics.”

I didn’t say anything. He was having the worst day of his life. If I could help by just listening, I’d do it.

“I became a climatologist to help save the world. To stop the nightmarish environmental catastrophe we were sinking ourselves into. And now…this. It’s necessary, but horrible. As a scientist yourself, I’m sure you understand.”

“Not really,” I said. “I spent my whole scientiﬁc career looking away from Earth, not toward it. I’m embarrassingly weak on climate science.”

“Mm,” he said. “Western Antarctica is a roiling mass of ice and snow. This whole region is a giant glacier, slowly marching to the sea. There are hundreds of thousands of square kilometers of ice here.”

“And we’re going to melt it?”

“The sea will melt it for us, but yes. Thing is, Antarctica used to be a jungle. For millions of years it was as lush as Africa. But continental drift and natural climate change froze it over. All those plants died and decomposed. The gases from that decomposition—most notably methane—got trapped in the ice.”

“And methane’s a pretty powerful greenhouse gas,” I said. He nodded. “Far more powerful than carbon dioxide.”

He checked his tablet again. “Two minutes!” he called out.

“All ships: Condition Red,” Stratt radioed. “Repeat: Condition Red.”

He turned back to me. “So here I am. Environmental activist. Climatologist. Antiwar crusader.” He looked out to sea. “And I’m ordering a nuclear strike on Antarctica. Two hundred and forty-one nuclear weapons,

courtesy of the United States, buried ﬁfty meters deep along a ﬁssure at three-kilometer intervals. All going oﬀ at the same time.”

I nodded slowly.

“They tell me the radiation will be minimal,” he said.

“Yeah. If it’s any consolation, they’re fusion bombs.” I pulled my jacket tighter. “There’s a small ﬁssion reaction with uranium and stuﬀ that sets oﬀ the much larger fusion reaction. And the big explosion is just hydrogen and helium. No radiation from that.”

“Well, that’s something.”

“And this was the only option?” I asked. “Why can’t we have factories mass-produce sulfur hexaﬂuoride, or some other greenhouse gas?”

He shook his head. “We’d need thousands of times the production that we could possibly do. Remember, it took us a century of burning coal and oil on a global scale to even notice it was aﬀecting the climate at all.”

He checked his tablet. “The shelf will cleave at the line of explosions and slowly work its way into the sea and melt. Sea levels will rise about a centimeter over the next month, the ocean temperature will drop a degree— which is a disaster of its own but never mind that for now. Enormous quantities of methane will be released into the atmosphere. And now, methane is our friend. Methane is our best friend. And not just because it’ll keep us warm for a while.”

“Oh?”

“Methane breaks down in the atmosphere after ten years. We can knock chunks of Antarctica into the sea every few years to moderate the methane levels. And if Hail Mary ﬁnds a solution, we just have to wait ten years for the methane to go away. You can’t do that with carbon dioxide.”

Stratt approached us. “Time?” “Sixty seconds,” he said.

She nodded.

“So this solves everything?” I asked. “Can we just keep poking Antarctica for more methane to keep Earth’s temperature right?”

“No,” he said. “It’s a stopgap at best. Dumping this crap into our atmosphere will keep the warmth in the air, but the disruption to our

ecosystem will still be massive. We’ll still have horriﬁc and unpredictable weather, crop failures, and biome annihilation. But maybe, just maybe, it won’t be quite as bad as it would have been without the methane.”

I looked at Stratt and Leclerc standing side by side. Never in human history had so much raw authority and power been invested into so few people. These two people—just these two—were going to literally change the face of the world.

“I’m curious,” I say to Stratt. “Once we launch Hail Mary. What will you do then?”

“Me?” she said. “Doesn’t matter. Once the Hail Mary launches, my authority ends. I’ll probably be put on trial by a bunch of pissed-oﬀ governments for abuse of power. Might spend the rest of my life in jail.”

“I’ll be in the cell next to you,” said Leclerc. “Are you at all concerned about that?”

She shrugged. “We all have to make sacriﬁces. If I have to be the world’s whipping boy to secure our salvation, then that’s my sacriﬁce to make.”

“You have a strange logic to you,” I said.

“Not really. When the alternative is death to your entire species, things are very easy. No moral dilemmas, no weighing what’s best for whom. Just a single-minded focus on getting this project working.”

“That’s what I tell myself,” Leclerc said. “Three…two…one…detonation.”

Nothing happened. The coastline remained as it was. No explosion. No ﬂash. Not even a pop.

He looked at his tablet. “The nukes have detonated. The shockwave should be here in ten minutes or so. It’ll just sound like distant thunder, though.”

He looked down at the carrier deck.

Stratt put her hand on his shoulder. “You did what you had to do. We’re all doing what we have to do.”

He buried his face in his hands and cried.

—

Rocky and I talk about biology for hours. Both of us are intensely interested in how the other’s body works. We’d be pretty lame scientists if we weren’t.

Eridian physiology is, frankly, amazing.

Erid is so close to its star, the sheer amount of energy entering the biosphere is ridiculous. And Eridians, being at the top of the food chain, have a heck of a lot more energy to work with than human bodies do. How much more? They have sacs in their body that just hold ATP—the main energy- storage medium of DNA-based life. Usually it lives in cells, but they have so much they have to evolve more eﬃcient storage for it.

We’re talking absurd amounts of energy here. They pull oxygen oﬀ minerals to get metals. Eridians are, in eﬀect, biological smelters.

Humans have hair, ﬁngernails, tooth enamel, and other “dead” stuﬀ on our bodies that serve critical purposes. Eridians take that concept to the ultimate extreme. Rocky’s carapace is made of oxidized minerals. His bones are honeycombed metallic alloys. His blood is mostly liquid mercury. Even his nerves are inorganic silicates transmitting light-based impulses.

All told, Rocky only has a few kilograms of biological material. Single- celled organisms travel through the bloodstream, building up or repairing the body as needed. They also manage digestion and service the brain, which sits safely in the center of his carapace.

If bees evolved to make hives that could walk, and the queen was as intelligent as a human, that life-form would be similar to an Eridian. Except the Eridian’s “bees” are single-celled organisms.

Eridian muscles are inorganic. They’re made of porous, sponge-like material sealed in ﬂexible sacs. The majority of the body’s water is tied up in those sacs. And the atmospheric pressure is so high, the 210°C water is still a liquid.

They have two separate circulatory systems: the “ambient” system and the “hot” system. The ambient blood is 210 degrees Celsius. But the hot blood is kept at 305 degrees, which is hot enough to boil water even at Erid’s air pressure. Both circulatory systems have blood vessels that expand or contract around the muscles as needed to set their temperature. Want to expand? Make it hot. Want to contract? Make it cold.

In short: Eridians are steam-powered.

Because of this, the ambient circulatory system ends up as the heat sinks when muscles are cooled. It constantly needs to be cooled back down to normal temperature, hence the radiator. Rocky “breathes” in a sense, but only to pass outside ammonia across capillaries in a radiator-like organ in the top of his carapace. Five slits at the top allow the air in and out, but at no point does any of it enter his bloodstream.

While Eridians don’t “breathe,” they do still use oxygen. They’re just much more self-contained than a human body. They have plant-like cells and animal-like cells inside. Oxygen to CO2, CO2 to oxygen, back and forth,

always kept in balance. Rocky’s body is a little biosphere. All it needs is energy via food and airﬂow to dump heat.

Meanwhile, the hot blood is too hot for any biological material to survive inside—it boils the water inside. This is handy for sterilizing incoming food of pathogens, by the way.

But in order for his worker cells to service any part of the hot-blood system, the system has to be cooled to ambient levels. And when that happens, the Eridian can’t use muscles at all. And that’s why Eridians sleep.

They don’t “sleep” like a human does. They’re legitimately paralyzed. And the brain, also being maintained, has no conscious function during that period. A sleeping Eridian can’t wake up.

That’s why they keep an eye on each other when they sleep. Someone has to keep you safe. Probably dates back to caveman (cave-Eridian?) days, and now it’s just a social norm.

As amazed as I am at all that, to Rocky it’s a boring topic. Meanwhile, he’s utterly shocked and amazed by humanity.

“You hear light, question?” Rocky says. (He puts a little quaver on the ﬁrst note of his sentence when he’s surprised or impressed.)

“Yes. I hear light.”

While we chat, he uses his many hands to assemble some complicated- looking piece of equipment. It’s almost as big as he is. I recognize several parts on it as things he’s been repairing these past few days. He can hold a conversation and work on delicate machinery at the same time. I think Eridians are much better at doing multiple tasks than humans are.

“How, question?” he asks. “How can you hear light, question?”

I point to my eyes. “These are special body parts that focus and detect light. They send the information to my brain.”

“Light gives you information, question? Enough information to understand room, question?”

“Yes. Light gives information to humans like sound gives information to Eridians.”

A thought occurs to him. He stops working on his device entirely. “You hear light from space, question? You hear stars, planets, asteroids, question?”

“Yes.”

“Amaze. What about sound, question? You can hear sound.”

I point to my ears. “I hear sound with these. How do you hear sound?”

He gestures all over his carapace and arms. “Everywhere. Tiny receptors on outer shell. All report back to brain. Like touch.”

So his whole body is a microphone. His brain must be doing some serious processing. It has to know the exact position of the body, sense the time diﬀerence between sound hitting diﬀerent parts of it…man, that’s interesting. But hey, my brain gives me an entire 3-D model of my surroundings just from two eyeballs. Sensory input is really impressive across the board.

“I can’t hear as well as you,” I say. “Without light, I can’t understand the room. I can hear you talk, but no more.”

He points to the divider. “This is wall.”

“This is a special wall. Light passes through this wall.”

“Amaze. I give you many choices for wall when ﬁrst build. You choose this because light pass through, question?”

It seems like so long ago—back when the divider was a mosaic of hexagons of diﬀerent textures and colors. I’d picked the clear one, of course.

“Yes. I chose this because light passes through.”

“Amaze. I gave choices for diﬀerent ♫♩♪♫ of sound. Never thought of light.” I glance at the laptop to check what that mystery word was. I almost never have to look at the laptop now. Still, once in a while there’s a chord I just don’t remember. The computer reports that word was “qualities.” Okay, I

can’t fault myself for not knowing it. That one doesn’t come up very often.

“Just good luck,” I say.

“Good luck,” he agrees. He makes a few more adjustments to the device, puts his tools back in his bandolier, then says, “I am done.”

“What is it?”

“Device keeps me alive in small room.” He looks happy. I think. He’s holding his carapace just a little higher than usual. “Wait.”

He disappears back into his ship, leaving the device behind. He returns with several plates of transparent xenonite. Each plate is a pentagon about a centimeter thick and a foot across. I hate myself for thinking in hybrid units like that. But that’s what my brain came up with.

“I make room now,” he says.

He assembles the pentagons edge to edge, using some kind of thick liquid glue from a tube to hold them together. Soon, he has two halves of a dodecahedron assembled. He holds them toward me proudly and places them together. “Room.”

The “room” is a geodesic sphere made of pentagons. The total diameter is about a meter. Easily big enough to contain Rocky.

“What’s the purpose of that room?” I ask. “Room and device keep me alive in you ship.”

I raise my eyebrows. “You’re coming into my ship?”

“Want to see human technology. Is allowed, question?” “Yes! Allowed! What do you want to see?”

“Everything! Human science better than Eridian science.” He points to the laptop ﬂoating beside me. “Machine that think. Eridians no have that.” He points to my toolkit. “Many machines there Eridians no have.”

“Yes. Come look at anything you want!” I point to the small airlock drawer in the divider wall. “How will you get it through that?”

“You leave tunnel. I make new divider wall. Bigger airlock.”

He pulls the completed device—which I now realize is a life-support system—onto his carapace and straps it on. It covers the radiator slits at the top of his carapace.

“Is that blocking your radiator? Isn’t that dangerous?” “No. This make hot air into cold air,” he says.

Air conditioning. Not what I think of when I see a species that lives comfortably at over 200 degrees Celsius. But we all have our tolerances.

He seals the globe around himself with glue. “I test.”

He just ﬂoats there for a minute. Then, he says, “Works! Happy!” “Great!” I say. “How does it work, though? Where does the heat go?”

“Easy,” he says. He taps one small part of the device. “Astrophage here.

Astrophage take all heat hotter than ninety-six degrees.”

Ah, right. To humans, Astrophage is hot. To Eridians, it’s quite cold. And it’s the perfect air-conditioning medium. All Rocky has to do is run the air over some Astrophage-ﬁlled cooling ﬁns or something.

“Clever,” I say.

“Thank. You leave now. I make large airlock for tunnel.” “Yes yes yes!” I say.

I collect all my belongings in the tunnel, including the mattress clamped to the wall, and stuﬀ them into the control room, then go into the control room myself and seal both airlock doors.

I spend the next hour tidying up. I wasn’t expecting company.