Archive of Our Own

Drunk and sad at grad school, Ryland got his first and only tattoo. 

It wrapped around his calf and there was a wobbly blown-out bit around the back because he caught the artist getting it wrong midway through a letter, and the moment he got it he instantly regretted it. It looked nerdy to a layman and corny to an expert, and when he dropped out of the field it was a constant reminder of the failures trailing behind him.

He told Rocky about this, because now there was a five-legged punchline to the story, and he'd long since run out of good anecdotes to share on the flight to Erid.

"What is a tattoo, question?"

"Uh, kind of like…" 

Ryland gestured vaguely to the carvings on Rocky's legs. Rocky perked up the way he did when he was trying to hear something small.

"Oh! Humans have [***]?"

"Kinda," he hedged, because actually he had no idea if that meant the same thing. Better qualify. "Not everyone gets them, but sometimes people get markings on their skin. And I got…"

Sitting up from where he'd been lying on the floor throwing a hacky sack in the air, Ryland gestured Rocky to his light-sight monitor and pulled up the leg of his jumpsuit. Rocky scanned the leg and nearly jumped.

"You have [***]!"

He tilted the scanner this way and that, intensely interested: Ryland shifted his leg around so he could read the whole thing. Rocky'd been getting good with written English so he didn't take long to puzzle it out, even through a hazy haptic screen.

"Letters. An equation. Why do you have equation as [***]?"

"You're gonna like this. It's called the Drake equation. It's a theory for how to calculate the probability of intelligent life on other planets."

Rocky put the scanner down. "Amaze." He paused. "Amaze amaze." 

He really did seem amazed: he had gone still like he was about to go to sleep. Hey, he wasn't wrong: the coincidence is pretty great.

"Right? I got that twenty years ago. Mostly because it was spring break and I'd had too much and I'd gotten dumped for the third time in three months. The guy I went to usually did four-leaf clovers and mom hearts so it's kind of ugly, but now? It's kind of cool."

It kind of was. The Drake equation was more of a thought experiment for astrobiologists than real science, but every bored academic plugs in numbers from time to time. Average rate of star formation, by number of planets that could form around a star, by number of planets likely to contain intelligent life, by intelligent species that would put detectable signs of life into the universe… Ryland usually put in higher numbers than most people in his field, because discounting the need for liquid water gets you better odds, but even then you usually get a crazy low likelihood. It's not just solving for intelligent life— it solves for the odds for intelligent communicative life, the kind of civilization you could talk to across space. 

Ryland, the day he got the tat, had noodled around until he managed to get the odds for humanity ever finding another species to talk to up at the dizzying high of 0.003729, and then he'd bought a bottle of Kahlua and slammed it. 

Now he was telling that story to an alien who could and did communicate, though right about now he wasn't talking at all. Wasn't doing anything, weirdly.

"Need word." Then Rocky shook himself. "No. You need word. New word: [***]. It means a pattern, an importance, a construction that means something. You put patterns on your body and it shows who you are."

Rocky put two of his legs in front of him, joining them together. It was the same thing he did when he first introduced himself: each leg had carvings in it, which matched into a single image when together. The symbol was complex. A canal-like shallow ditch ran diagonally down across both legs, and from that central valley a series of carved lines crisscrossed away from it in straight paths. Zigzags, parallels, and right-angles, they seemed at first random but the majority were moving from the center of the ditch to the outside of his leg.

"Name [***]," Rocky said. He then separated the legs and pointed to the leftmost, rubbing the place he always rubbed when he talked about Adrian. It was a green spot that looked like an emerald Venn diagram had been inlaid into his stony carapace. "Mate [***]." 

Then he shifted, showing another leg entirely, the one with the carving of a circle, lines coming from it, the largest in the shape of a Petrova line. "Purpose [***]."

"Let's go with tattoo," Ryland said. "Does everyone on Erid have them?"

"Everyone. No, well, there are some without, but they're strange. Hard to explain. Every Eridian you are likely to meet will have a name tattoo and a purpose."

Rocky traced the Petrova line on his leg. "This was the most recent part. Finishing a purpose tattoo takes a long time, long long long time. Some never finish theirs in their life. It is stupid to get any part too big, get too confident it will remain important. Or I thought that once. And then I carved this." He stroked it, back and forth. "We all did."

Ryland chewed the inside of his cheek. The thought of Rocky's crew made him sad at the best of times, but everyone carving how important the mission was into their skin, all of them matching… God, he'd teared up once just looking at Yao and Ilyukhina's matching mission patches. 

"I'm sorry."

Rocky continued to sadly stroke the Petrova line. "The stupidest Eridians," he continued, "get purpose tattoos early in life before they've even started their purpose."

Ryland nodded. Then he blinked. "Hey!"

Rocky hummed amusement, shaking out of his reverie. 

"I joke. Or not whole joke. But there is an Eridian story: old story, sixties of thousands of years old. Every Eridian culture has a version. The Eridians in these stories know the future before it happens, and get their purpose tattoo. In some stories, sad ones, they know their future and get a tattoo to avoid that purpose, and the future finds them anyway, or even because of the tattoo. In other stories they get their tattoo to change or be the future: to be at the right place when they are needed. Thousands of years ago, it was normal to choose a purpose tattoo because an Eridian thought they knew the future. Now it is a strange thing to do, only done by strange or stupid Eridians, but it still… It is a very old story. I do not believe that story."

"New word," Ryland said, his mouth dry. "Superstition. Believing something that's likely not to be true. Something that doesn't happen in science."

Rocky named it in turn. "Superstition. I do not believe in superstition."

"I don't either," Ryland said. "I have the tattoo because I studied astrobiology, and I'm here for the same reason."

"I know. It makes sense."

Even still, he could practically feel how spooked Rocky was, and it was spooking him right back.

"What does the equation calculate the probability to, question?"

"Everyone has a different answer. I thought it was under 0.004."

"When we get to Erid please never tell this story," Rocky said, shifting from leg to leg. "It will only make strange Eridians stranger. Nobody will know it is there."

Ryland nodded, rubbing his calf and staring at the expanse of empty space out the window. "No problem, buddy."

"And they will think you are stupid," Rocky added, which earned him a hacky sack direct to the hamster ball.

Being the only ambassador for your species to a spacefaring civilisation who could go to war with you if they really, really wanted was kind of stressful for the first few weeks. 

It occurred to Ryland a few thousand times in those weeks that when he gifted Rocky a laptop, he'd also given a species the intel on how to build a nuke, and he'd never been great at doing introductory small talk even when he was doing it to creatures from his own planet.

Eventually that stress went away, or Ryland just stopped thinking about it as much, and mostly because there was just so much to learn. He was living an astrobiologist's dream, even if it meant he was fourteen light years from home and he could only live inside life support systems. 

Still, issues were starting to pile up. Rocky had gone out of town for a few weeks to visit the families of the crewmembers on the Blip-A that had died, along with some official functions Ryland didn't grasp the purpose of. Ryland had about three dozen questions about Eridian social niceties that he really needed to figure out before he had a meeting next week with some important political-sounding figures, and there was no Rocky to ask. For instance, every Eridian always turned their purpose tattoo to him after introducing themselves with their name tattoos, and a lot of the more important Eridians seemed kind of weird and formal about it. Ryland could say his name back, but he never knew what to do when they presented their purpose tats, and awkward silence didn't seem to be the right response. 

At least the scientists were easy to talk to: until they asked him about crazy curveballs.

"What magnetic [***] is most pleasing for you, question?"

Ryland checked the translator. He didn't need it as much anymore, but some Eridians spoke dialects he didn't catch too well and there were always new words to learn. This Eridian had a dialect he barely understood at all and used new words all the time. He isolated the sound and readied to play it back. "Sorry, what does [***] mean?"

"Apologise: [***] is the movement magnets make in the body. Does that understand, question?"

This scientist was new, and had flinched hard when they first saw Ryland: a lot of Eridians did, and Ryland still sometimes jumped when he saw a bunch of giant spiders wandering in his peripheral vision, so he wasn't offended. Still, the scientist had seemed on-edge ever since, only barely introducing themselves— Ryland was running out of arbitrary names to give and had landed on Gonzo. Unlike most Eridians, Gonzo had been kind of cursory with their purpose tattoo, shrugging it vaguely towards Ryland before launching into questions that mainly involved magnets.

"Movement magnets make in the body," Ryland mused, before it clicked. "Resonance? Magnets moving hydrogen atoms in the body?"

"Hydrogen," Gonzo repeated. "Confirm translation question? Hydrogen is single proton atom, hydrogen is no neutron atom?"

"Confirm," Ryland said.

"Repeat first question: what magnetic resonance is most pleasing for… no," Gonzo said, cutting themselves off so hard on a note that it went from a C sharp to a C flat. They tapped their leg absently against the ground, which usually meant an Eridian was trying to see something better, but sometimes just seemed to mean they were thinking really hard. "Grace body resonates magnetically with hydrogen question?"

"Confirm."

Gonzo tapped the ground again, and warbled something in such a low register that Ryland couldn't catch it all, but the translator picked it up. Gonzo jumped guiltily when the laptop obediently repeated Human body strange as it is ugly.

"Apologies apologies apologies!" Gonzo yelped, shifting like they were going to leap for the door. "Meant only that human body does not resonate as expected with magnets! Meant in good way! Eridian language from [***] uses word to say something that sounds bad when excited by difference!"

Ryland suppressed a laugh, because seeing an open wet mouth tended to freak out the new guys. 

"It's okay! Seriously. The answer to your question is that Earth hasn't got as strong a magnetic field as Erid, twenty five times weaker, but the difference isn't high enough to cause any damage to me. We have machines for seeing illnesses in the human body, thirty thousand times Earth's magnetic field, and only then does magnetic resonance start to cause problems."

"Thirty thousand," Gonzo repeated. "Damage only at thirty thousand times Earth magnetic field of calculated 0.42 gauss question?"

"Yep. Erid's magnetic field should be fine."

"Because human body only resonate with magnetic field with hydrogen atom," Gonzo repeated: they sounded like they were repeating it to themselves. "Machine for human sickness aligns hydrogen protons. Do humans even sense magnetic direction, question?"

Ryland had suspected Gonzo was some kind of specialist, because while he'd only gotten a glance they had a really involved, messy, kind of crazy looking crisscrossy purpose tattoo. Gonzo was anxious enough to have called a space alien ugly on the first meeting, but they knew the magnetic resonance for a hydrogen proton offhandedly and had made some pretty amazing jumps of thought from there. Textbook academic. Also, what?

"No! Do Eridians?"

"Yes!"

"So what, you know what way north is without anything to tell you?"

Gonzo pointed thoughtlessly in a direction, which Ryland would take on trust was north. "Yes! How do humans go anywhere on planet? How do humans not get lost?"

"We do a lot," said Ryland. Some humans might be better at orienteering than others but he was the only one here and he completely sucked. He'd gotten lost once trying to walk to a Jack in the Box drive thru. "Many humans have died from getting lost, but we get around that a bunch of ways. We invented magnetic needles floating in liquid to point north, and draw maps, and thinking machines we put into orbit that tell us where we are on other thinking machines, and we use the sun for direction."

Gonzo raised an octave, their whole body turning like they weren't sure what direction to hear the answer from. "You use the sun for direction question?"

"The sun rises to the east and sets to the west with each planetary rotation, and at night, there's a star that generations of humans have used that points north."

"Stars as direction," Gonzo said. "Not important to magnetic questions Gonzo needs to ask. Very important to Gonzo scientific curiosity, statement."

"Eridians sensing magnets very important to Grace scientific curiosity too, statement. It's cool to learn about."

"Good good good. Cool to learn about also. I have studied magnetic resonance one hundred eighty years, I have never thought half of what you tell me. Sensing magnetic resonance of hydrogen protons is so much magnetic field it would rip Eridians apart. Not studied. Theoretical. Interesting. Cool. Cool cool cool. I am learning nothing important for dome construction. I and [***] thrum made the magnetic resonance machine in the Blip-A for the comfort of crew. Asked to return to construct pleasing resonance for you. Not needed. Apologies for time waste."

Gonzo started for the door, and Ryland tossed the dice. Of anyone he could ask, if Gonzo wasn't likely to come back to the dome construction team and already kind of owed him one for the 'ugly' line, this was probably the safest start on getting to grips with tattoo etiquette.

"Hey, before you go?"

Gonzo practically shot back. "Yes."

"Does your purpose tattoo mean that you study magnetic fields?"

Gonzo tilted their whole body back and forth at the laptop translating the question. They slowly shuffled their body so that the arm with the purpose tattoo was as far from Ryland as possible.

"Long answer. Purpose of question, question?"

"Humans don't have purpose tattoos," Ryland said, though that was kind of a blanket statement. "Scientific curiosity. Culture curiosity."

"Understand." Gonzo shuffled again. "Difficult answer for Gonzo. I will answer, but Grace should ask more Eridians. I do not have normal answer."

He'd definitely asked something wildly inappropriate, oh god. Here come the nuke nightmares again. "Oh, you don't need to answer if it's not a… I don't even know what it is. Sorry. I'm new here."

Gonzo made a noise that Ryland had figured was kind of like Eridian laughter. "I am not offended. Scientific curiosity. You are another species from another planet. I only apologise for bad answer. Gonzo is [***]. Do you know this word?"

"No."

"Means [***]."

Ryland checked the laptop, toggled around a few octaves just in case, but no dice. "Sorry, I don't know that either."

Gonzo tilted their carapace. "Do not add to thinking machine. You know the word thrum?"

"Sure," Ryland said, who only vaguely felt he got the picture on those, but he knew the basics. Eridians can't predict when they sleep and they never sleep alone, so most Eridians worked at the same place they lived, and those were called thrums. Thrum was also a word for a kind of mass argument-song-debate thing that Eridians did too, but using the same word for argument as for a hundred-person flatshare made sense to him. 

Gonzo shuffled again so their arm with the tattoo was in front, presenting it, and Ryland shifted closer to the xenonite barrier in the meeting room to see. They traced a few lines in the center of the tattoo, shallower than the others.

"Once I was in [***] thrum. I adjusted laws in [***]. This was that purpose tattoo. I was unhappy. I changed my purpose. Removed as much of old purpose as I can. Joined [***] thrum for magnetic studies. This is my new purpose."

Gonzo traced the deep slices that crisscrossed over the top of the old tattoo, spiralling out and out across their arm.

"Many Eridians do not allow purposes and thrums to be changed. Others do not respect Eridians who have changed a purpose tattoo. I am happy in my new purpose, and do not regret it." Gonzo paused, tracing the old lines. "I do not regret old purpose also. Regretted once but not now. This is true to life I am."

Ryland looked askance at the translator, because he was going to try and ask a qualifying question and he was scared that whatever words he was going to use would be insanely offensive in a way he wouldn't guess. "So you… changed your career?"

Gonzo tapped two fingers on the ground with a fidgety, rhythmic click. "Yes."

"Oh, okay," Ryland said. "Huh. So once an Eridian chooses their job, they do it for life?"

"Not all. Gonzo did not. Most do."

"Weird," Ryland mumbled to himself, and the translator obediently translated. Gonzo flinched, and he winced. "Not weird like weird! I'm sorry! I was talking to myself how it's weird that— humans don't do that is what I mean. We change our jobs all the time."

Gonzo's entire body language changed all at once. "Confirm translation: humans change purpose frequently?"

"Yeah," he said. "Confirm. I've had half a dozen jobs over the years. The reason I ended up on the mission is because I was an expert in astrobiology, but I'd dropped out and become a teacher by the time astrobiology became important enough that we needed to send anyone to space about it."

Gonzo did the Eridian equivalent of a double-take. "You had left the purpose that was your cause for space travel when you went to Tau Ceti question? You were a teacher at time of mission question? Teacher is education of young question? You were not astrobiologist at time of mission question? Confirm?"

This was steering dangerously close to a subject that Ryland had only told Rocky, would only ever tell Rocky, and had sworn Rocky to secrecy on just before they got to Erid. Only now was he starting to suspect that for Eridians, there was a whole other scandalous layer on top of that story that he didn't even realise. He really, really needed to talk to Rocky. 

"Yeah," he said, untangling that and trying to focus on the part that wasn't a secret. Or maybe should be a secret on Erid? Was being an ex-scientist ex-schoolteacher astronaut going to get him arrested? Unfortunate thoughts of nukes and vivisections crept back from the rear view, and Ryland tried to think happy thoughts. Gonzo was currently regarding him with full, amazed attention. "Yeah, I was— you've got to tell me if this is weird to Eridians, Gonzo—"

"Yes, will."

"It's normal for humans to have a lot of jobs, but I thought I was going to be an astrobiologist for life. I loved it, but there was a whole thing with a research paper, and maybe calling someone a waste of carbon at a conference, so I quit the field and went into teaching. And I loved teaching. I was really good at it. But when astrophage arrived, they thought I might be the guy that could find out the answers…"

Ryland vaguely waved a hand, gesturing around the whole 'ran away like a coward and got amnesia-drugged into helping humanity' deal. 

"And now I'm here."

Gonzo was silent for a moment.

"I promised answer. I will answer. Grace purpose change, and change again, and change back again, is very, very, very, very strange to Eridians."

"Strange as we are ugly," Grace agreed with more levity than he felt, feeling kind of crushed that he'd somehow managed to find the one alien society that, if they knew the whole truth, would find his whole story even more cowardly than humanity would. 

"Do you regret your purpose choices?" Gonzo asked.

"Uh," Ryland said eloquently. "Nhh. No. No. I've got some regrets but not… it's a mixed bag. I'm glad I went to space and I'm glad I'm here. I don't think I've got the whole zen mindset you've got on it."

"Do not understand word."

"Calm mindset."

"I am not calm about any thing at any time," Gonzo said, tapping the inlaid partner sigil on their arm: a kind of shale-grey spiky ball. "Mate will agree. Purpose tattoo has meant many problems many times for me. I have regretted, I have been angry, I have known I was wrong. But I was not wrong. Or I was not wrong in every purpose. Gonzo was wrong in the purpose I was in. I am now happy, but not calm. It is good exchange."

Ryland nodded, blinking hard because Eridians get weird about faces leaking. "Yeah. I'm with you on that."

"Grace purpose tattoo would be more messy than Gonzo purpose tattoo," they said with a gentle tap of their arm. "Could not see purpose for lines."

"I couldn't for a while, actually," Ryland said, swiping as fast as he could at his eyes. He really should have named this guy something cooler than Gonzo. "I don't know what my purpose is anymore, but I think I've had a big enough purpose for a lifetime now."

"Grace okay question?"

"Yeah."

"Gonzo has answered purpose tattoo question, question?"

"Yeah. Thank you for answering."

"Thank you for telling me about hydrogen proton machine," Gonzo said with a little jazz hand wave. "I have many ideas now."

"Wait. Did anyone tell you about radiation?"

"Do not understand word. Confirm translation as hot hot very fast gas, question?"

"Ohhhkay. Oh wow. Uh. I have my next meeting in…" Two minutes. Darn. "I think we definitely need to talk about magnetic fields in the dome more. Like a lot more."

Gonzo tilted cautiously. "Grace said magnetic resonance in dome not needed."

"Grace knows human science about magnets that Gonzo would find really really really cool, and Grace needs at least one pointless meeting a day or he's going to go crazy."

"Not serious question."

"Serious about magnets. Only a little serious about going crazy."

Gonzo bounced on all their arms at once. "Grace! Grace is very cool statement!"

"Gonzo is very very cool statement," Ryland said, jazz handsing back at Gonzo. 

Ryland had just spent three hours reviewing sand with the mineralogy team, who, he noticed, all had very similar purpose tattoos that looked kind of like sand. Everything was sand. He lived in a sand world. There was grainy sand and dark sand and sand with weird glowing blue inclusions he was kind of afraid to handle, and while he appreciated everyone was here working all day every day on the perfect zoo enclosure to keep him from going stir crazy, he was also going stir crazy looking at sand. 

"Hi Grace! I see we have not killed you yet!" 

Rocky rolled into the temporary life support box Ryland lived in 24/7, and he could have cried from relief. He gratefully pushed all the sand back through the meeting room airlock, trying to be polite about definitely cutting everyone's important meeting time short, and the mineralogy guys made annoyed chirps as they left. They'd get over it: he hadn't seen Rocky in a month.

"Hey bud, how was it?"

Rocky gestured to the little bedroom pod, which was, at Ryland's pointed and desperate request, windowless and soundproofed from the rest of the place. Every Eridian on his life support team knew he didn't need to be watched when he slept, but a cultural norm that ingrained had proven really hard to ignore. The compromise was a cuff that checked his vitals when he slept, and the upsides ranged from a private place to masturbate without being heard by every Eridian in a five hundred foot range to having somewhere he and Rocky could gossip.

"Most thrums were nice," Rocky said, settling down with Ryland criss-cross-criss-cross-legged in his ball on the mattress. "Many were sad I did not have remains to share, but knew they were not likely to see them again and so had accepted this years ago. I was told not to mention or explain radiation. I told everyone every time. A lot of powerful people dislike me now, but I am only disliked by a small number of crew families."

"Is that gonna be a problem?"

"No," Rocky said, shrugging two arms a little. "I think it will be fine. We saved Erid. The atmosphere is warming again and the planet is in a happy mood. I can use that power and this time to say things other Eridians are not able to. I don't give them enough reasons yet to stop me."

That last sentence had a weird wobble to it that, without his translator, Ryland had to concentrate hard to understand. "What's going on?"

Rocky waved a hand in the air, annoyed. "All of Erid thinks I have become… word. [***]. Not normal actions because of broken logic. Need stopping or help. Not the word insane. Not the word sick. Less strong."

"Uh. Eccentric, maybe. Or crazy."

"The second word sounds more funny when you say it, use that. Crazy. Most think I was crazy once and no longer am, but some believe I still am. Everything I do is watched. Only here is not watched, and only because I made this room myself."

"What? You're not crazy."

Rocky didn't have eyes, but never underestimate a species' ability to give you a hard stare. "Grace, I was the first Eridian you met. I have known you five years already. You have met all other Eridians for two months. I am your normal Eridian."

"If you're giving me weird habits you better stop, everyone already finds me strange."

"Oh, shut up. You cannot be normal to an Eridian with an inside out wet face. Like an [***]."

"Like what?"

"It is an alien invasion movie," Rocky said; movie was his word for the Eridian equivalent, which was like if VR was made out of a really good surround sound system. "You look like the alien from [***]. Its meat is outside its body and it smears its acid moisture on Eridians to erase their tattoos and dissolve their carapace. Your mouth is wet like that."

"Oh, thanks, now I feel way better."

"Now I don't find it disgusting," Rocky said awkwardly, his multitonal whistle unconvincing even to a human ear. "The point I am trying to make is that you do not know when I do something strange and when I do not. All Eridians speak the same language, but your translator uses the unusual way I say 'yes'. All Eridians watch each other sleep, but I broke many cultural rules by demanding to watch you. All Eridians have a thrum, but…" 

Rocky shifted, uncrossing his legs, leaning heavily against Ryland's side. Ryland leaned back: he kind of had to, or Rocky would tip him over.

"...I had no thrum," he said in an almost inaudible trill, "for forty-six years. It is not normal. Very not normal. Many Eridians would rather die than be alone for a year. The mission chose more individualistic people, and I am, but there is a limit. We are more of a communal species than humans are, I think."

And many humans would rather die than be alone for the equivalent human time. When Ryland thought he'd die alone in space he started drinking vodka from an IV. He gets it, and he was alone for weeks after the coma, not forty-six years.

"So they think you went crazy alone."

"They think I went crazy when I met you," Rocky said. "I took risks no sensible person should have while on a mission that would kill my species if I did not complete it, all to meet another living being. I chased your ship. I threw information about my species and the address of my home planet at your ship when I still had no idea if you were a threat. We were both there for the Petrova line, but I did not know that then. And then I joined our ships with a tunnel. I begged to watch you sleep. I moved into your ship. I risked my life and with it the whole of Erid to save your life."

Ryland had long since given up on avoiding the 'leaky space blob' complaints from Rocky, so he let the tears flow. Rocky didn't say anything this time, which was actually kind of worrying. 

"You're making it sound worse than it is," Ryland said, although the risking-his-life part was unquestionable. "Even if you were lonely, you'd been working the astrophage problem for forty-six years and not found an answer. You saw an astrophage-powered ship and took a smart risk."

"There are those on Erid who now say my thrum is Earth," Rocky said, with an angry shiver in his voice. "That I should sand down my purpose tattoo and carve in a human form. Some just think I am crazy from loneliness but others believe I am hiding a new purpose, I am a traitor, and that Earth is hostile to Erid."

Ryland blinked. "Okay, so when I asked if this was gonna be a problem and you said it was fine you were a lying liar, is what you're telling me."

"New word. [***]. Person who complains at other person for action first person does all the time."

"Hypocrite," Ryland said, swallowing down the shock. Rocky shifted away from leaning on Ryland, sliding down inside the ball like a puppet with his strings cut. 

"Sorry. Sorry, Grace. This month has felt like three months. It is fine. Promise. It is as fine as possible. Only a small number of Eridians are suspicious of Earth: the evidence is clear and widely shown to the planet that you saved us. There will always be some that do not trust a good thing to be good."

"We saved us," Ryland said, staring at Rocky's limp form, the way he was tracing the Petrova line carving on his arm.

"You know what I mean." Rocky made a noise that, if it was a word, Ryland didn't know it. It didn't sound like a word. "I am sorry for calling you a hypocrite."

"I learned about how purpose tattoos work the other day," Ryland said; he knew this place was soundproofed but he lowered his voice anyway. "How changing purposes works. You know everything about me. If anyone can call me a hypocrite it's you."

Rocky made that same not-a-word noise again, which from the irritated trill Ryland started to suspect was like a sigh, or a groan. "Do not tell me you were told about [***], question."

Ryland hadn't put the word down in the translator, because Gonzo had told him not to, but he recognised it. "Yeah."

"Two months on Erid and already you know [***]," Rocky muttered. "Purposes are not part of human culture. Human jobs are not the same."

"But I guess it makes what I told you about ten times worse."

Rocky shifted in the ball, sitting up, sounding serious.

"Tattoos change. We add to them. Adding is not taking away. You added and added over the top of every line and those additions meant we lived. I did not know when I joined the aerospace engineering thrum that I would one day add a Petrova line to my tattoo. Eridian culture considers that a change that is normal to a purpose tattoo, but that is a change too. Becoming a biologist then a teacher then an astronaut would change a purpose tattoo in a way many Eridians would consider uncomfortable, but without you we would be dead."

"You know what else," Ryland said, drawing up his knees to his chest and staring at them.

"You were scared."

"I was a coward."

"You were scared. I was chosen because I was the kind of Eridian who would be chosen for a dangerous engineering mission with a risk of death. And I went crazy anyway. You were chosen because they could not choose anyone else. You completed the mission anyway."

"Maybe." It was going to take a long, long time before any evidence of the Earth's sun brightening up would reach Erid, and Ryland dreaded it never would.

"We lived. It would not be the way either planet would have chosen it. They are saved. Both were saved. We are alive and they are too, so now we can all thrum at each other about how we did it all wrong."

"I don't think you're crazy," Ryland said, forehead pressed hard to his knees now.

Rocky shifted one arm a little from underneath himself, still limp in his ball. "I do not think you are a coward."

They sat in silence, or the best Ryland could manage until he'd calmed down. Rocky eventually moved again into a more comfortable sitting position, quietly moving a finger up and down the washboard 'goodbye' carved into his arm while humming a song. Rocky threw a few choice notes into the song until it formed a sentence, twining with the sound of Eridian music.

"Your face does look like it will smear acid on my carapace and melt it, though."

Ryland uncurled and laid sideways on the mattress, the side of his head against Rocky's ball. Then he licked the ball. Rocky jolted back like he'd, well, seen a spider.

"Ugh, Grace! Grace, disgusting!" 

Ryland wiped at his tongue, spitting on the floor. "Eugh, that tastes like used kitty litter."

"Did you just eject liquid too, question?! Everything I said I take back," Rocky whined, twisting the ball back and forth to try and wipe the saliva onto the mattress: it was only smearing more. "Humans are out to destroy us. I declare war on Earth."

"We're going to get goo on everything you love," Ryland crooned, licking his hand and pressing a sticky handprint to the flexible xenonite panel, pushing into the ball. Rocky erupted in a cacophony of tones that nearly deafened him, scrambling away from it with every limb.

"Not invited to thrum. Ejected from thrum. I'm putting you back in space myself. This was predicted by your unnatural future telling purpose tattoo, this was all predicted that you would do this! Back in space you go in a ball smaller than this one. A wet ball. Setting fire to human planet and sending astrophage to every star that might have more of you. Grace, no! Grace!"

The beach was perfect. The house was perfect. The dome was perfect: expensive and secretly completely pointless magnetic shielding included. 

The classroom was the last thing that got added, and that took the longest time out of any of it.

Erid's big guns had embraced the idea that Grace wanted to give back to the species, and they'd welcomed the concept of including him in a biology or astrophysics thrum, but when he asked about teaching instead, it had brought up a lot of questions that they didn't totally like the answers to. Rocky had helped smooth the way and drafted him a statement that seemed to really calm a lot of people down, even though to Grace's eyes it looked like the same words in a different order with some added tonal variation for kicks. 

In the end, Grace was an honorary member of three thrums, which Rocky tried to explain the cultural reaction to and settled amusedly on "modern", and most importantly he was a teacher again. Teaching a bunch of kids with eidetic memories seemed like a beautiful utopia at first, before he realised how much a kid with five limbs and music for language could mess around in a class, but the local teaching thrum were godsends and taught him all the tricks of the trade. Eridian children were individually shy and hated being singled out for questions even more than human kids but if you gave them a chance to all try and shout the same answer together they'd scream your ears off. Heaven.

Except he kept getting questions from all of them about his tattoos. Same as how Eridians struggled to believe that he didn't want someone staring from above him when he slept, the kids couldn't believe that he never got a name tattoo, not even as a hatchling, and he didn't have a partner tattoo and never had— and this one really got to them— a purpose tattoo. He'd fended this off once, twice, three times, and then little Ripley, who unbeknownst to themselves had earned a name Ryland had been saving for a favourite student, tapped the ground twice and asked:

"But if humans don't have tattoos, teacher Grace, how will you know what you love?"

Adorable, and Grace figured he'd go for a risky social teaching moment that Gonzo would love and a lot of stuffy Eridians would hate. He got some flack for it from parents and the bigwigs at the teaching thrum that he and his teacher drinking buddies all bitched about later, but it wasn't that bad and the kids seemed happy with the answer.

The question stuck with him, weirdly. Stuck with him for days, then weeks, and then a month, and then he looked at the one blown-out letter on his calf tattoo one morning and got himself something sharp he could sterilise.

"I leave for three weeks and I hear nothing except 'Rocky, you need to see Grace', 'have you seen Grace', 'have you heard Grace lately'. Is there some kind of— oh."

Grace sat just above the waves, Converse digging into the wet sand. He smiled over at Rocky. He was fully clothed, and the waves were loud, and he was thirty feet away, but Rocky's hearing was just that good. "What do you think?"

"I need to hear them better, you crazy fucker," Rocky yelped, sprinting across the sand and sliding into a heap beside him, yanking at his pants leg. 

"Woah, a please would be nice!"

"How did you do this, question?"

"When human skin is damaged, we grow it back but it's not totally the same and on me they tend to get ridged up, so there's kind of a—"

"You damaged yourself question?!" 

"Not in a bad way!"

"Oh, the good way that you damage yourself!"

"There are a handful of human cultures that do this, I'm just borrowing from them. It's fine, I'm not going to make a habit out of it."

"Humans did this to begin with and you acted this whole time like it was a strange new alien concept!"

"Tattoos are different! We were talking about ink under the skin before, not scarification."

"I'm never talking to you again." 

The sound of Rocky's voice, which was a borderline out of control warble, suggested differently. "So you like them?"

"Yes, I like them," Rocky said, around the Eridian equivalent of a full-volume sob. "You still cannot tell the story behind this." 

Rocky pointed to the Drake equation, which Grace had very neatly and carefully traced, even the wobbly part. 

"They don't know it was there before."

"They cannot know, I will kill you if you make any of what we did look like it's supernaturally fated, Eridians will start making daily psychic pronouncements on the radio again if we tell them. Oh, Grace." Rocky traced the other lines that spiderwebbed across his shin, voice wobbling. "How did you do this one?"

"I took a picture last time you were here."

He hadn't totally copied Rocky's purpose tattoo, that would be weird even for them, but he'd wanted the star and the Petrova line emerging from it to be as close as possible. He'd added in some flourishes that were common to the biology thrum, the astrophysics thrum, and the teaching thrum, and then he'd thrown in a smiley face for his own amusement and for future scholars to question.

"Worried," Rocky said, and then broke off. He started up again, getting his voice in check. He pulled Grace's pants leg back down and patted it awkwardly. "I worried about meeting other humans, in future. Most Eridians tell each other apart, make legal choices, identify the dead, from the shape of their tattoos. It's stupid, but I worried about not being able to tell you apart from other humans. If you died, if I had to identify you."

"Oh, Rocky. C'mere."

"Hugging," Rocky said with mild annoyance, but launched himself into the hug anyway. Grace squeezed him tight, tracing lightly across the place on Rocky's arm, under the suit, that the Petrova line ran. 

"If you're ever seriously worried about that," Grace said quietly into the hug, "all humans have unique fingerprints, so you can just figure us out that way."

"All humans have what."

"Fingerprints." He sat back from the hug and held out a hand, though he doubted with the soft ground and the waves and the suit that Rocky would be able to hear the difference. "We have these patterns that go into our skin right here, people use them to prove their identity."

They both sat silently for a minute, and Ryland considered how easily he could change his identity, right now, when he was the only human on the planet.

"You have patterns carved into your skin that only you have that identify you as you and only you, and you spent the last eight years pretending you didn't know a single thing about purpose tattoos?! Question?!"

"Okay, I can see how you think that's the same when I say it, but it's not the same! They're—"

"—I'm going to kill you and the humans will come to this planet and ask where you are and I'm going to say humans question? I not know humans statement. Found strange space blob in space, leaked all the time, left at Tau Ceti," said Rocky, and Grace laughed, sprawling out on the cool wet sand of home.