HØLLY

So wait, is Grace a child in this AU? - NO. Grace is still a full grown adult human in this AU. He is still mentally an adult. He just has the Eridian form of a pebble! Grace retains all memories, skills, and mental capabilities of an adult in pebble form. Instead of his Eridian form roughly matching Rocky's age (late 200s early 300s (earth years)), he is a pebble in his mid 30s (earth years).

Is this AU age play? - NO. This is NOT age play. Grace may act childish, and Rocky may experience parental instincts, but neither of them are doing age play. There is an in world explanation for why Grace is acting a bit childish or child-like at the start of this AU, and it has to do with the biological differences between his bodies. Rocky's parental instincts are a mix of all Eridian's natural instinct to want to protect/help a lost/abandoned/stray pebble, but also because prior to their departure to Tau Ceti, he and Adrian had been talking about having a clutch. The combination of that conversation, natural instincts, and the fact that Rocky was already protective over Grace in human form combine to make him go a little wild over pebble Grace. They do not and will not develop a parent-child relationship.

What does Pebble Grace look like? - same post I linked in the other masterpost. Eridian Shifter Grace and Pebble Grace look identical except for size and carvings. Pebble Grace's carapace is in fact slightly smaller than the Earth beanbag.

How will his two bodies age? - essentially, this is sort of/kind of/not really the same answer as the question in the main au's FAQ. Pebble Grace will not age quickly to "catch up" to match his mental age (like to match Eridian Shifter Grace's size). It's really hard for me to write out, actually? His human form will not wither and die and leave him only with his Eridian form. Now that I'm thinking about it more, I sort of realized I have to even more handwave this. Anyway. Yes. This does mean that Rocky and Grace will not age the same. One of them will always outlive the other. (I don't actually think this answer makes sense so uh. pretend it does)

Fanart!!!

THE wenber1234 drew pebble shifter grace!!! including several moments from chapter 1 of Rocky the Pebblesitter!!!

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! I MADE THE BETTER POST

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.

Theres a THIRD time travel au!!! Post where I talk about it is HERE. Grace wakes up on Erid prior to the Blip-A leaving, but no one else remembers!

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)

How does Grace's scar/carving work? - this post has me talking in detail about how Grace carves Rocky's handprint into one of his limbs.

How does the food situation work for Grace on the way to Erid? Can he eat Eridian food in human form? - this post here has me talking a bit about that!

Fanart!!!!!

the amazing jessthephantom drew Grace, Rocky, and Adrian from You May Call Me Grace, including the scene where Grace runs into walls while trying to get the gifts he made for Adrian!!!