What if... my two favorite pieces of media met.
Lone Echo and Project Hail Mary crossover AU
If you don't know what Lone Echo is (many of you don't), it's a PCVR only game where you play as a robot Echo Unit named Jack.
SPOILERS AHEAD!!
You live on the space station the Kronos II that orbits Saturn. It's a dig site that digs out materials from the bigger meteorites that also orbit Saturn.
You, as Jack, work with the captain of the site, Olivia Rhodes, AKA Liv. During your time here at the site, an anomaly, or a singularity, shows up near the face of Saturn. It disrupts systems within the ship and you have to go and fix them. Over time, the singularity grows and ends up collapsing. The collapse results in a ship from the future thar YOUR company built. It's called the Astrea. While that happens, the Kronos II is destroyed, killing the life support and you get damaged. While you, as Jack, are damaged and getting rebooted, Liv ventures out into the Astrea in hopes to find some sort of life support.
As you reboot, your mission is to find Liv in the Astrea. Since it's from the future, something.... bad came along. This thing is called the biomass, an infectious fungus that feeds off of any sort of energy source. The Astrea is covered in the biomass. You have to maneuver your way through the ship and through the biomass to find Liv. On the way, you find Apollo, the ship's AI. You work together with him as you help him repair the ship and he helps you find Liv.
After you find Liv, life support starts failing once more. In your last hope of survival, you recreate the situation that happened when the Astrea completed a time jump. You jump forward in time 400 years. The year is now 2526.... ish. This is the timeline the Astrea is originally from. However, it's different. Due to some infected parts of the Astrea being left back in 2126, it spreads, and now there's barely any humanity left to survive. Your new mission is to find a cure to the biomass with Apollo and Liv. You find some friends along the way! In the end, you destroy the biomass and fix it.
Anyway, now that we have THAT lore aside, onto the AU!!
My idea is that Jack, Apollo, and Liv are all exploring and have completely fixed the astrea over time. They want to try to make another time jump for some more scientific research to see if they can find where the biomass originated from. They unfortunately did something wrong during the jump and it put them into the wrong year.... a century into the past. 2026. In a completely different solar system, nonetheless. They find themselves near Erid, orbiting the planet alongside the Hail Mary (that looks absolutely miniscule next to the Astrea)
Eridian scientists (with the help of new technology from Grace) are able to detect a new 'object' beside the Hail Mary. They realize it's another ship and they send recruiters up to investigate.
When the eridians get up there, they find Jack and Liv. Over time of communicating thru translators they finally come to the agreement that Jack, Liv, and Apollo will all go down to erid.
This is where it gets tricky... Jack has never experienced gravity before. We don't know if his systems will run properly or if his shell can even withstand constant weight like that.
Liv, Jack, and Apollo come to a compromise to just send Liv down. They hope that the eridians have some sort of environment that's suitable for her. While Liv goes down to Erid, Jack and Apollo (mostly apollo) work on a new shell together that can withstand the gravity levels of Earth as well as training him on well... walking. He never needed to walk before so he never learned.
You know I really need to just write a fic about this... I'm working on it guys trust.