Magic Feline

FAQ:

What is this AU about? - The Eridian Shifter AU is a Project Hail Mary AU created by thederpypikachu98. Grace develops the ability to shift between his human form and an Eridian form at will a couple of weeks after the Adrian Fishing Incident. Canon diverges from that point.

Is this AU based on the movie or book? - both! I actually prefer the movie, but I read the book several times after it initially came out. Aspects of the book canon are present, but things lean more towards movie canon, like Grace's scar, the Hail Mary ship design, Grace's slutty glasses, and how Eridians look.

Why can Grace change into an Eridian? - in the AU's canon? they can't figure it out. if you're asking me, the author? ...because why not? it's For The Plot

What does Eridian Grace look like? - this post here includes a description of both Eridian Grace and Pebble Grace. His appearance is also described in the first fic in the series, and includes Grace's own thoughts on his Eridian form. (tl;dr: he thinks he looks similar to Earth and that he's pretty!)

Is this AU a Grocky AU? - Nope! Grace is aroace and I pull a lot from my own personal experiences for him. Rocky and Adrian are mates, and Grace is their third in a queerplatonic way. I see Grace and Rocky as soulmates - not romantic, not platonic, but that third thing, the QPR thing! If you read them as romantic, great, but know that it is not canon to the AU and I do not write them as romantic.

How does Grace's age work? - This will take some explaining. I roughly have human Grace as being in his mid 30s ish during the events of the book/movie. The quick version is that whichever form Grace is in is the one that will determine how both forms age in that moment. For example: If Grace is in his human form, his human form will age normally. Even though he is not in Eridian form, his Eridian form will age proportionally to the time he's spending in human form, so it will age much faster than an Eridian normally would. If he is in Eridian form, his Eridian form will age like it should, and his human form will drastically slow in its aging. So if he were to spend an Earth century in Eridian form and changed back to his human form, his human form would have only aged about an earth decade (ish). But if he spends say 20 Earth years in human form, his Eridian form will have aged by around 200 Earth years. If that doesn't make sense, I apologize, I'll make a better post about it soon and link it here!

Can Grace's human form survive in Erid's atmosphere/pressure, since his Eridian form can survive in both atmospheres? - Nope! Grace's human form remains mostly the same, save for a few things. He does develop an eidetic memory in both forms, and has perfect pitch when singing or humming, but he cannot survive Erid's atmosphere. If Grace were to step onto the surface of Erid in human form without protection, he would die painfully. Why? Because I tried to make it work and I struggled too much with it.

So Grace won't starve/will have an easier time on Erid? - Grace will not starve on the way to Erid! Rocky brings all the rations that he can and once Grace runs out of human meals, he only eats in Eridian form. He also won't have to wait to go down to Erid's surface when they get to Erid (as seen in the Adrian POV fic).

What about the biodome? - sadly, the foggy beach dome does not exist in this AU. Since Grace can just be an Eridian, he actually ends up preferring to be Eridian there, since it's easier for everyone to understand him and for him to be with Rocky and Adrian. They do build a small dome, so they can study and use human technology, and so Grace can occasionally go human for them to study or so they can learn how to use some technology.

Does Earth find out about Grace being able to turn into an Eridian? - NOPE! (Not yet!) Even though Grace starts being able to shift prior to him sending off the Beatles, and even though Mary has plenty of footage of him shifting or existing as an Eridian, he does not tell Earth. I imagine that the data on the Beatles has to be manually uploaded. So Grace got to select what files, logs, and footage got sent back. During the time Rocky was recovering post-fishing trip, he prepped a lot of stuff for the Beatles. After that, things picked up, and then he didn't update them with the latest Taumoeba and mission info until he decided to go back for Rocky. At that point, he was so focused on just sending everything that he only threw in a couple of logs where he's human and then launched them. So Earth has no idea that Dr. Ryland Grace can also turn into an Eridian!

Will they visit Earth? - Yup! Grace, Rocky, and a crew of Eridians design a new ship and venture off to go visit Earth. This is the plot of the main fic!

Does Grace have any disabilities, mental illnesses, etc? - Yes!!! In my AU, Grace is autistic and has ADHD (like me!). He also has PTSD and depression (understandably).

Does Rocky have any disabilities, mental illnesses, etc? - Yes!!! Rocky is also autistic (or like the Eridian equivalent). They also have PTSD, anxiety, and depression. One of his legs is also damaged/split, and does not have any fingers/claws, just like in the movie.

How do pronouns work in this AU? - It's complicated? I know Andy Weir has said something about pronouns being hierarchical, but eh. I'm taking that and twisting it. Imagine that whenever a fic is in an Eridian's POV (or Grace once he gets used to Erid), they are using hierarchical pronouns based on status/honor/respect/etc, but when translated to English and other human languages, they are all essentially translated as they/them. Sort of. It's less that there are hierarchical pronouns and more that there are tones and chords and inflections in an individual's name. In English, Rocky likes he/they pronouns, Grace starts off with he/him, and Adrian uses they/them. Later, Grace will have some gender thoughts (or lack of gender) and will feel more comfortable with they/them even in human languages! Until that fic has been posted, I am referring to Grace mostly with he/him, but know that yeah, Grace will prefer they/them in the future.

How big are the Eridians? - check out this post for the most up to date height chart. It also includes Pebble Grace!

What happens to Grace's clothes when he shifts? - check out this post for my current explanation. tl;dr it has not been decided yet. sometimes it disappears with his human form and sometimes it shreds/falls off. at some point it will be decided which option is canon and all fics will be edited accordingly

You've mentioned other AUs/spinoffs, are you planning on posting those? What are they? - I have posted the first chapter of the Eridian Pebble Shifter AU, in which everything is the same except Grace's Eridian form matches his chronological age, meaning he's a pebble. (masterpost). (the following are split up but still are the same answer to this question. an attempt to make it easier to read)

There are also 2.5 time travel AUs of this AU that will be posted at some point, but both require the main fic to really get going. Yes, 2.5. 1 is where Grace and Rocky are in the Mary docked at the space elevator and they get thrown back in time so the Mary is orbiting Earth during the time when past!human!Grace is on Stratt's Vat doing science. Everyone is very shocked by this new version of Grace, who is Buff, Confident, best friends with an alien, and tears Stratt a new one the first time they see her (also apparently has done some thinking and is agender and does not care about human gender norms anymore).

The 2nd and .5 time travel spinoffs are basically the same spinoff just slightly different. Both Grace and Rocky's memories get thrown back in time to the same time period that the other time travel spinoff takes place in. In one version, Grace instinctually shifts into his Eridian form, which they're more comfortable in by that point, and bolts from the deck in front of hundreds of humans who lose their shit. they barricade themself in a room and have several panic attacks before eventually managing to get stratt to give them a lab, get them the materials to make xenonite, and to get everyone to chill out so they can be eridian and be more comfortable. the other version is where the same circumstances occur but grace doesn't shift in front of everyone and desperately tries to pretend to be their old self but everyone catches on very quickly that something is Very Not Right.

there's also a "watch the movie" au that i've started but i havent gotten far because of focusing on the main au and the other spinoff aus.

How does Eridian time work? What is base-6? - I go over how time on Erid works and what base-6 (and other numerical systems like base-2 and base-10) work in this post here! (be warned. it is very long. i got very very excited)

-Grace did not design the body himself, but was encouraged to pick a phenotype to grow it from so he opted for an orange colouration and the genetic traits that came with it. The science behind growing the body was based on the me-burger experiments.

-The body was grown to be older than Grace’s human age to make sure he would still be seen as a mature adult, but he’s still somewhat younger than Rocky.

-He requested having the scar of Rocky’s handprint tattooed onto one of his arms.

-He struggled with finding his balance and voice at the start, and grew a bad habit of not fully using the mobility of his fifth limb, either slightly dragging it or keeping it raised and out of the way. This resulted in a lot of tripping and stumbling but he figured it out eventually! …Mostly!

-He was able to pick up the language pretty fast since he was already familiar but his voice remains pretty “flat” sounding to other eridians. This is a somewhat uncommon but not rare speech impediment on Erid, akin to human stutters, so he gets by okay and most eridians might just struggle reading his emotional tones until they get used to it. At the start this made him hesitant to use his voice but Rocky and Adrian were quick to encourage him into several scientific yap sessions to make him more comfortable!

But, Grace survived so much gear: malnutrition, burns, knocks and bruises... at first it seems like he recovers, but as the years roll on, the damage starts to take its toll.

He lived longer than he was originally meant to, based on standard human life expectancy. But, obviously, by Eridian standards... Grace hasn’t lived long enough, has he?

I digress.

Grace passes away, the Eridians throw a funeral for him, and they put up a memorial statue at his grave inside the habitat dome they built for him. This dome stays open to the public for a bit of remembrance and for scientific and academic study.

The thing is, Rocky is clearly gutted by the loss of his human mate. And it takes Adrian an absolute age to pull him out of that depressive state.

For at least a couple of decades, Rocky goes almost every day to spend a couple of hours near Grace’s grave. It’s his way of finding a bit of solace.

Work getting a bit much? He heads to Grace’s statue. Had a barney with Adrian? He goes there to calm down. Want to hear the ocean waves where his best mate loved to swim? He’s there.

But then, tragedy strikes.

Since Grace’s dome had become open to the public, plenty of folk could get in. Usually, it was Eridian scholars or those wanting to pay their respects. But some Eridian committed a murder. The dome was shut to the public for the crime scene, then for decontamination.

For a couple of years, Rocky couldn't get in, as the contamination was proper rank and they had to restore a lot of the gear in the dome.

But it was enough.

When Rocky finally arrives at his usual spot inside the dome... the first thing he clocks is a tiny Eridian egg, half-hidden in a dodgy excavation in the disturbed earth of Grace’s grave. And, miraculously, the egg seems to be sound. Its shell and the earth seem to have protected it well enough.

All hell breaks loose.

The authorities rock up, wondering how any absolute shithead could do something so atrocious. An unhatched egg left in such a shambles. No one to blame, no one to take the fall. Whose egg was it?

Rocky refuses to budge from that tiny egg.

They haven't found a parent. The Eridian version of Social Services doesn't have a clue what to do with the egg 'cause they’re terrified it’s a dud, or that suddenly plunging it into Erid's atmosphere will snuff it out.

Rocky—with Adrian backing him up—decides to keep the egg.

And, weirdly enough, it seems to help Rocky a bit.

Adrian sorts out a nursery, a proper nest, some blinding toys, and anything else a pebble might need.

Rocky knocks the toys up himself, builds a kid's version of the Hail Mary in his cave (like a treehouse) for when the pebble grows up and can have a bit of a play. He makes sure there’s a load of recordings of Grace teaching his students available so the pebble can learn from the best teacher in the world.

But nothing happens.

A bit of time passes. Rocky and Adrian take turns keeping it warm, tending to it in the nest, slowly getting it used to the proper Erid atmosphere... well, they do what they have to do to make sure it becomes a healthy little pebble.

...And he’s the clumsiest pebble of the lot, tumbling and rolling about inside the nest until he ends up on his back. Rocky wanted to blub (just like Grace did), absolutely chuffed and overwhelmed seeing the little lad make it.

After staring at him for a few seconds, Adrian names him Grace.

Grace the Pebble! He doesn’t seem to have a cracking echolocation system. He needs Rocky and Adrian to even know where he’s got to inside his nest.

Grace the Pebble! Despite all the graft to get him used to the Eridian atmosphere, he’s... "soft" by stone standards. (I don't know much about rocks; someone would have to tell me what kind of stone is considered soft or malleable, but that’s Grace all over).

Grace the Pebble! He seems to feel both "cold" and "hot," always wanting to be wrapped up in something. And he starts squawking if Adrian or Rocky nick the blanket or cloth he’s wearing.

Grace the Pebble! Who doesn’t seem to have a shred of decorum when it comes to eat, seeing as he’ll tuck in right in front of Rocky and Adrian or any other adult looking after him.

Grace the Pebble... well, he’s anything but graceful, 'cause he’s incredibly clumsy; one of his paws is a bit dodgy, so he almost always uses four to get about.

Grace the Pebble!... when he finally learned to chatter, the first things he came out with were "Rocky" and "Mary."

It took a couple more years, and a fair few strops and therapy sessions. But both Adrian and Rocky realised that, somehow, Grace had come back to them.

Though, a tiny Grace the Pebble! telling Rocky that he’s a shameless, bossy git was all it took for Rocky to put two and two together.

Grace was back, with them.

https://archiveofourown.org/series/6034951 fanfic link!

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