Chapter Text
It was another six hours before we were finally able to leave. We were both on edge, aware that we were still in a precarious position. Luckily I didn't have to spend the whole time waiting idly. The beetles were currently attached somewhat haphazardly to the ship. I had been careful while zeroing our rotation, but if we tried to turn even their tiny engines on full they would tear themselves right off the ship.
Grace used its 3D printer to create a model of the Hail Mary's internal structure for me, and while it did its maths I set to work designing and creating new supports for the beetles. It wasn’t too complicated, but it kept me busy. And it was interesting to see the Human design sensibilities that had gone into building the structure. I really hoped I’d have a chance to chat with a Human engineer someday and learn more about their methods and thought process.
Eventually the maths was complete, the supports were built, and Grace did yet another EVA to add them to the places I had indicated. By the time we were in the control room preparing for departure I was a mess of nerves.
" Ready? " Grace asked from its seat.
"Ready," I confirmed. I had the control boxes for the beetles in front of me again. We had decided it would be most efficient if I kept controlling the beetles while Grace monitored its screens for information about our trajectory. I had watched Grace's attempts at multitasking before and now didn’t seem like a good time for it to try and improve on the skill. Besides, I'd already gotten a good feel for them when I'd been cancelling our rotation.
" Okay... John and Paul to 4.5% "
"John and Paul, 4.5%" I made the necessary adjustments, and there was a very small amount of force on the ship as the beetle's thrusters came on.
" John and Paul to zero. Ringo to 1.1 percent. "
"John and Paul zero. Ringo 1.1"
We went back and forth like this a few times, gently nudging the ship to the angle that we needed, the one that would hopefully lead us back to my ship if Grace’s maths was right. It took a lot of fine tuning but we eventually got the ship positioned at the correct angle.
" Here goes nothing. " Grace said, " All ahead full! "
"John Paul Ringo, 100%" I confirmed. I dialled all three beetles to their maximum speed. Grace was thrown back against its seat by the acceleration, and I gripped two handholds to keep myself in place. My insides buzzed anxiously, remembering how it had felt to be tossed around during the catastrophe. But this force was still well below Erid gravity and I maintained my grip easily. Even Grace adjusted to it quickly.
" Maintain thrust for three hours, " Grace said, and unstrapped itself from the chair.
"Three hours. I watch engines. You relax," I suggested.
" Thanks, but no time for rest. Want to use gravity while I can. " I managed to keep my reaction mostly internal. Grace had done a lot of intense work over the last 12 hours, including two EVAs, one of which was in gravity, and six hours of complicated mathematics. It should really take a break for a while.
But it would take 11 Earth days to get back to my ship, assuming nothing went wrong, and during the majority of it we would have no gravity. I could understand why Grace wanted to make the most of its scientific equipment while we could actually use it. Still, it would be nice if my friend would take better care of itself.
It was only three hours, I reminded myself. After that it would be forced to slow down for a while.
"I stay here. Tell me how experiments go."
" Will do ." I listened as Grace headed down the ladder towards the lab. The Taumoeba experiment was still set up just as it had been before the ship had shut down. Originally Grace had intended to check on the experiment after an hour, but that had been almost 100 hours ago. There just hadn't been any time to deal with it during the outbreak.
I turned my attention back to the engines. My screen watcher was set up to monitor Grace's screens. Grace had gone through the display with me again before we'd launched, to make sure that I understood which numbers were indicating what. Everything seemed to be at the expected values for the time being.
Idly, I picked one of my hands up and let it drop to the floor, testing the new gravity. The low gravity had been helpful during mine and Grace's early recovery, but it was kind of nice to be at higher levels again. It still wasn’t quite right, but it was closer than I’d been since the journey to Adrian.
Sometimes I wondered if I would recognise Erid gravity when I felt it again. I had existed weightlessly in this system for many, many years. Now I had had the experience of Earth gravity, half Earth gravity, one and a half Earth gravity, and a brief and terrifying experience with six times Earth gravity. I didn't like to think that the gravity of my own world might be unfamiliar to my muscles.
Well, I had adjusted to a lot of strange things during this ship. I would just have to trust I could handle adjusting back to life on Erid.
My thoughts were interrupted by the sound of Grace in the lab. Its breathing had changed to something shallow and unsteady. That typically was not a good breathing sound. It stepped over from the Venus tank to the Threeworld tank, and I could hear its hands shaking. I didn't like it.
"What you see?" I called down. What I wanted to ask was “Are you okay”, but there was something very volatile in its demeanour just then.
" Failure. " Grace said, still shaking, " Both experiments. The Taumoeba are dead. "
For a moment I could barely process what it was saying. Dead. They were all dead. We'd failed. We had worked, and fought, and almost died, and almost died again , and we had failed. I don’t consider myself an angry person, in the moment I was utterly overwhelmed by how deeply unfair it all was. So much work. So much effort. So much hope . All wasted.
I balled one hand into a fist and slammed it into the wall of my bulb so hard that it hurt. I didn't worry about breaking it; I would crack long before the xenonite did.
"Anger" I growled. Grace wasn't faring much better down in the lab.
" All of this work. All of it for nothing. Nothing! " It slammed one of its own fists down onto the lab table, shaking everything on it. " I gave up so much for this! I sacrificed so much! "
The anger in me rose, and rose, until it felt like it was going to burst out of me. And then suddenly it all dissipated. Gone like smoke. In its place I felt hollow, like I hadn't felt since discovering Grace's ship. I slumped heavily to the floor. In its lab Grace was still at the table, bent over to rest its head in its hands.
We stayed like that for a long time, wallowing in despair. For a while I allowed myself the luxury of pure grief, untainted by messy things like hope and determination. Because what was I supposed to hope for now? We had done everything we could, risked everything we had, and we had failed. How were we supposed to keep going after this?
Keep going. For so long I had kept going because I was in freefall with no ground to catch me. Continuing was all my momentum would allow me to do. But meeting Grace had changed that momentum. It had allowed me to change course, to do something different. But it also meant I couldn’t rely on it to carry me forward. If I allowed myself to, I could come to a stop here. I could just let it all be over.
Or I could keep going. On purpose this time. I flexed the fingers of the hand I had used to punch the wall. It still ached a little from the impact. My carapace still ached from when it had broken open too. My entire being ached from all the loss, and loneliness, and hopelessness of almost 50 years in space. But despite everything, I wasn’t dead just yet. Slowly, carefully, I picked myself up off the floor.
"We work more," I said, loud enough for Grace to hear, "We no give up. We work hard. We are brave."
Grace was quiet for a moment, then breathed out heavily. " Yeah. I guess so. " But it didn't spur into action. Instead it sat down heavily on its seat in the lab with its head facing down at the table. The anger seemed have left it too, and now it just seemed vacant.
I knew what it was like to come up against a wall like this. Before Grace arrived, all I'd had were walls. No matter what I did I hadn't been able to move forwards, because I lacked the equipment, the skills, and even the basic knowledge to do what needed to be done. I knew how much it hurt.
But things were different now. We had each other. I checked the screen watcher's readouts; We had been stable this whole time, all the numbers holding in the expected ranges. It would be fine if I left it for a moment, so I left my bulb and climbed down to the lab. Grace didn't register my presence at all, but I didn't interrupt it. I just took a seat and waited for it to be ready. Finally its head lifted to face me.
"You are very sad." I said.
" Yeah. "
"I am sad also. But we not be sad for long. You are scientist. I am engineer. Together we solve."
Grace threw its arms into the air angrily. " How?! "
I stood, and walked down the tunnel until I was as close to Grace as I could be. "Taumoeba eat all your fuel. Therefore Taumoeba survive and breed in fuel-tank environment."
" So? "
"Most life no can live outside its air. I die if not in Erid air. You die if not in Earth air. But Taumoeba survive when not in Adrian air. Taumoeba stronger than Erid life- stronger than Earth life." Grace turned to face me. It had to bend its head all the way back to do it from where it was sitting.
" True. And Astrophage are also pretty tough. They live in vacuum and on the surface of stars. "
I clicked two fingers in agreement. "Yes yes. Astrophage and Taumoeba from same biosphere. Probably evolve from common ancestor. Adrian life is very strong." Mycelium would have admonished me for being so reductive. No kind of life was "stronger" than other life. All life was evolved for its particular niche, with all the specificity that entailed. But that didn't matter. What mattered was the way Grace's face had changed.
It straightened up. " Yeah. Okay. "
"You have idea already. Not question. I know you. You have idea already. Tell idea."
" Well.. Venus, Threeworld, and Adrian all have a bunch of carbon dioxide. The Astrophage breeding zone in all three is where the pressure is 0.02 atmospheres. So maybe I'll start with a chamber full of pure carbon dioxide at 0.02 atmospheres and see if Taumoeba survives that. Then add in more gases one at a time to see what the problem is. "
"Understand."
Grace got to its feet. Despite it all I felt a twinge of excitement to hear it getting back into action. " I need you to make me a test chamber. Clear xenonite with valves so I can let air in and out. Also I need to be able to set temperature to -100 o C, -50 o C, or -82 o C. "
"Yes yes. I make now. We are team. We fix this. No be sad."
I started down my tunnel towards the dormitory to work on it. Grace checked its miniature on its arm. " The main thrust ends in thirty-four minutes ." It said, " After that's done, let's use the beetles to put ourselves in centrifuge mode. " That made me pause. We had both agreed that it was best not to try and deal with rotation while we were in transit.
"Dangerous."
" Yeah, I know. But we need gravity for the lab and I don't want to wait eleven days. I want to make good use of time. "
"Beetles arranged for thrust, not rotation."
" It's worth the risk. " Grace insisted. Okay, so it was in one of its stubborn moods again. Sometimes it seemed like Grace would arbitrarily decide that something was worth arguing about, and it was so difficult to get it to listen to reason. I came back fully into the lab to try anyway.
"Ship will rotate off-axis. No can unspool centrifuge cables. Would tangle." I explained patiently. Grace should already know all of that, because it was the one that had explained it to me when we had first been planning how to cancel the ship's rotation.
" We'll create the needed rotation first, then shut off the beetles, then unspool the cables. " That made me so aghast I drew back a little, as if I could hide from the idea.
"If ship not unspooled, force is too much for Human."
Grace considered this, and for a moment I dared to hope that it was going to listen to sense. I probably should have known better. Presenting a scientist with a reason they can't do something triggers their innate puzzle solving instincts.
" Okay... How about this: I'll lay down in the storage room under the dormitory. That's the closest to the centre of the ship I can get. The force will be smallest there. I'll be okay. " Oh, so it wasn't even planning to be properly secured to a seat for this. This plan was getting better by the moment.
"How you operate a centrifuge controls from the storage room?"
" I'll.... umm... I'll bring the lab's control screen down there with me. I'll run data and power extension cables from the lab to the storage room. Yeah. That should work. "
"What if you unconscious and no can operate controls?"
" Then you cancel the rotation and I'll wake up. "
"No like. Alternate plan: Wait eleven days. Get to my ship. Clean out you ship fuel tanks. Sterilise- make sure no Taumoeba. Refill with fuel from my ship. Then can use all functions of you ship again."
" I don't want to wait eleven days. I want to work now. "
"Why?" I asked in frustration, "Why no wait?" Grace paused for a moment, considering how to answer.
" Human thing. " It said finally, like that settled the matter. I really wished there we weren't separated by our atmospheres so I could shake some sense into it. I also really wanted to keep arguing with it, but I could tell that it wasn't going to get us anywhere. Grace had found its determination again, and it was using it to insist on the least safe, least sensible path forwards. But at least it was choosing to move forwards.
"Understand." I said, wearily. "Not actually understand but... understand."
***
The Space Catan control system worked perfectly. I'd recovered it from the cool box, where I had used it to work on the beetles, and after a little bit of fine tuning I got it set up on the wall in the dormitory. It took Grace a little bit of practice to get used to, but then it was able to interact with the pieces exactly the way an Eridian would.
It would have been a great way to pass the time if Grace hadn't been so busy. The rotation had gone about as well as we could have hoped; Grace claimed the gravity hadn't been a problem, although it had seemed shaky for a little while afterwards. But Grace was entitled to make its own terrible choices about its health. Over the last two cycles it had done nothing but obsess over the Taumoeba. Not that I didn't understand the fixation. The survival of my world was also at stake, after all. I just wished it would slow down a little.
For two cycles it mostly shut itself in its lab, only taking breaks to eat and sleep. Those would have been less regular too, but I was monitoring it to make sure it didn't work itself into illness. I can be stubborn too when I need to be.
It was a very uneventful trip for me. Technically there was much more on the ship that needed repair now, but a lot of it was Human science equipment that I did not know how to fix. Strangely though I still felt a lot less anxious than I had on the trip to Adrian. Having actual and present dangers to worry about was somehow a lot less taxing than worrying about things in general. At least now I knew what things I needed to monitor.
And Grace did seem to be making progress. It hadn't told me much about its findings yet, but most of its mutterings were either curious or confused, rather than frustrated or despairing.
Early in the third cycle I heard Grace calling to me from the lab. I was in the control room, checking on our progress. Grace had made sure to keep the screens on the same setting most of the time, so that I would know where all the information was.
" Hey Rocky! " It said, " Watch me pull a Taumoeba out of hæt ! " I had no idea what a "hæt" was, but it sounded like Grace finally had something to share. I left my bulb and climbed to the lab tunnel.
"I assume that is Earth idiom."
" Yeah, Earth has entertainment called ‘ ˈtɛləˌvɪʒən ’, and- "
"Do not explain please. You have findings?" I was sure whatever ˈtɛləˌvɪʒən was was very interesting, but I really wanted to hear about whatever Grace had found.
" I have some results. "
"Good good." I settled myself down nearby, so I wouldn’t fidget while it was talking. I was a little anxious about whatever it might have found. Grace didn't seem upset about it though, which was promising. "Tell findings!"
Grace gestured to the equipment I had made " This functions perfectly, by the way. "
"Thank. Tell about findings."
" My first experiment was Adrian's environment. I added Taumoeba and a slide covered in Astrophage. The Taumoeba survived and ate it all. No surprise there. "
"No surprise." I agreed. "Is their native environment. But proves equipment works."
" Exactly. I did more tests to learn Taumoeba's limits. In Adrian air, they can live from -180 o C to 107 o C. Outside that range they die. "
"Impressive range." I commented. That was a range of almost 300 o C. The upper range made sense. It could survive temperatures a little warmer than Astrophage, which was at the very least a major food source for it, if not its main food source. -180 o C was interesting though. That was more than 100 o C lower than the environment it lived in. Did the temperatures in the upper atmosphere drop much lower sometimes?
But that was a mystery for another time. The salient information was that it could easily survive in the temperatures of Venus and Threeworld.
" Yes, " Grace agreed. "Also, they can survive in near vacuum. "
"Like your fuel tanks."
" Yeah, but not TOTAL vacuum. They need carbon dioxide. At least a little bit of it. I made an Adrian environment but put argon in instead of carbon dioxide. The Taumoeba didn't eat anything. They stayed dormant. Eventually they starved to death. "
"Expected. Astrophage need carbon dioxide. Taumoeba from same ecology. Taumoeba also need carbon dioxide. How they get carbon dioxide in fuel tanks?"
" I had the same question! So I did a spectograph of my fuel-bay sludge. There's a bunch of CO 2 gas dissolved into the liquid. "
That was surprising. But I only had to think about it for a moment before an answer presented itself. "Astrophage probably have carbon dioxide inside. Or decomposition creates carbon dioxide. Some percentage died in fuel tanks over time. Not all cells are perfect. Defects. Mutations. Some die. Those dead Astrophage put carbon dioxide in tanks."
" Agreed ."
"Good findings." I said. It was a lot of good information about the tolerances of Taumoeba. I stood up, to head back to the control room, but Grace stopped me.
" Wait. I have more. Much more. " I stopped.
"More? Good."
Grace leaned against its lab table, patting the testing tank. " I made Venus in this tank. But not quite Venus. Venus's air is 96.5 percent carbon dioxide and 3.5 percent nitrogen. I started with just the carbon dioxide. The Taumoeba were fine. Then I added nitrogen. And the Taumoeba all died. "
I lifted my carapace in surprise. "All die? Sudden?"
" Yes. In seconds. All dead. "
"Nitrogen... unexpected."
" Yeah, very unexpected! " Grace agreed, " I repeated experiment with Threeworld's air. Carbon dioxide only: the Taumoeba were fine. I added in the sulfur dioxide: The Taumoeba were fine. I added the nitrogen: Boom! All the Taumoeba died. "
I tapped a claw against the wall, taking all that in. "Very very unexpected. Nitrogen harmless to Erid life. Nitrogen required by some Erid life."
" Same with Earth. Earth's air is 78% nitrogen. "
"Confusing." I said. The evidence strongly suggested that life on Earth, Erid, and Adrian were all distantly related. Our DNA simply had too much in common to be a coincidence, given our proximity in space and the evident existence of life able to travel between stars.
So if nitrogen was harmless to all life on our worlds, and some life forms from both our worlds even needed nitrogen, why would it be so deadly to Taumoeba? Presumably whatever ancestor had seeded our worlds had been fine with it, or life would never have begun on Earth and Erid. And even Astrophage must have no problem with it, because it was thriving on Venus and Threeworld.
It was an interesting question. But it also didn't really matter, in the short term. In the short term the only thing that mattered was that we really had failed. It hit me all at once; Threeworld and Venus both had nitrogen in their atmospheres. Nitrogen killed Taumoeba. We couldn't remove the nitrogen from the equation, which meant Taumoeba would be useless on those planets. My carapace sank.
"Situation bad. Threeworld air is 8% nitrogen." Grace sat itself on a seat, knotting its arms together in front of it.
" Venus's air is 3.5 percent nitrogen. Same problem. " I sank even further.
"Hopeless. Cannot change Threeworld air. Cannot change Venus air. Cannot change Taumoeba. Hopeless."
" Well, " Grace said, before I could slump too far into depression, " We can't change Threeworld or Venus's air. But maybe we can change Taumoeba. " Well that was an interesting proposal. Did Earth have the technology to do something like that? And more importantly, was it available on the Hail Mary?
"How?" I asked.
Grace picked up the flat thinking machine from the table, and tapped on the screen to find some information. " Do Eridians have dɪˈzizəz ? Sicknesses inside your bodies? "
It was asking about diseases, but I had no idea where it was going with it. "Some. Very, very bad."
" How does your body kill diseases? "
"Eridian body closed. Only opening happen when eat or lay egg. After opening seals, area inside made very hot with blood for long time. Kill any disease. Disease can only get into body through wound. Then is very bad. Body shut down infected area. Heat with hot blood to kill disease. If disease fast, Eridian die." I was lucky that the Hail Mary was a very sterile environment, and I hadn't gotten any infections after the damaging my carapace during the catastrophe. If that had happened I definitely would have died.
" Humans are very different. We get diseases all the time. " Grace said. That made a lot of sense; Grace had five open orifices just on its head, and the eyes also presented a potential entry point. And its exterior was so soft it probably got damaged all the time. It really was a wonder that they had survived long enough to become an intelligent species.
" We have very powerful immune systems, " Grace continued, " Also we find cures for diseases in nature. The word is ˌæntibiˈɑtɪks 1. "
I tilted my carapace curiously. "No understand. Cures for diseases in nature? How?"
" Other life on Earth evolved defences against the same diseases. They emit chemicals that kill the disease without harming other cells. Humans eat those chemicals and they kill disease but not our human cells. "
Huh. I had no idea that was possible. Was that a technique we could employ on Erid, or did it only work with Human biology? "Amaze. Erid no have this."
" It's not a perfect system, though. Antibiotics work very well at first, but then over the years they become less and less effective. Eventually they barely work at all. "
"Why?"
" Diseases change. Antibiotics kill almost all the disease in the body, but some survive. By using antibiotics, Humans are accidentally teaching diseases how to survive those antibiotics. "
"Ah!" I said, understanding, "Disease evolves defence against chemical that kills it." It was the basis for all evolution, essentially. An environmental pressure was introduced, and the organisms that survived would breed and produce more organisms that were likely to survive that pressure.
" Yes. Now think of Taumoeba as the disease. Think of nitrogen as the antibiotic . " I thought about it for a moment, and then my carapace raised in excitement.
"Understand! Make environment barely deadly. Breed Taumoeba that survive. Make more deadly. Breed survivors. Repeat, repeat, repeat!" Grace was suggesting a kind of targeted evolution. Taumoeba had a very short doubling period, which meant we could breed many generations of it over a short period of time. All we had to do was create the correct environmental conditions that would ensure that only the Taumoeba with the traits we needed were bred. It was simple, it was elegant, it was a perfect solution!
" Yes, " Grace said, " We don't need to understand why or how nitrogen kills Taumoeba. We just need to breed nitrogen-resistant Taumoeba. "
"Yes!"
" Good. " Grace slapped a hand down on top of the testing tank. " Make me ten of these, but smaller. Also provide a way for me to get Taumoeba samples without interrupting the experiment. Make a very accurate gas injection system- I need exact control over the nitrogen quantity in the tank. "
"Yes! I make! I make now!" I scurried away along the tunnel to the dormitory. There was so much energy in my body I felt like I was going to shake apart. This was it. If we could breed nitrogen-resistant Taumoeba, then we would be done. We could go home.
The longing hit me again, so strongly that it hurt. I had to sit on the floor of the dormitory to try and calm down. Home. Since meeting Grace I had been trying to hold onto hope, but it had always been tempered by the fear that I would hurt myself with it again. I had lost many- figurative- fingers to that particular tool.
But now I was close enough to our goal to hear it. Now all of the feelings that I had been unconsciously holding back came flooding over me. I wanted to go home. I wanted to sleep in a normal room without worrying that a system malfunction would kill me before I woke. I wanted to run and run and run and never run out of room to just keep going. I wanted to hold someone's hand again. Adrian's hand, if it was still available to me.
I allowed myself a few more minutes to let it all wash over me. Then I picked myself up off the floor and got to work. There was one more hurdle left to overcome, and I wasn't going to do it by sitting around.