BloodyMary where Simon wakes up on the Hail Mary before Grace.
Like, the universe blinks and some space/time phenomenon runs afoul of Simon's elder god moment and the next thing he knows, he's waking up inside some kind of space ship(?) that appears to be running on autopilot.
It's weird and the tech looks both dated and brand new, expensive and advanced but also extremely retro, like someone using a diamond-encrusted rotary phone to check their emails. Luckily it's all mostly in language that Simon can comprehend, unluckily a lot of the equipment still seems like it would require several degrees of expertise to operate. But eventually Simon figures out enough to find the ship's crew, and... it's not looking good for them.
Two of them are dead. Have been for a while. Whatever stasis system(?) they have has preserved the corpses pretty well, but it's past the point of being able to try and revive them. The other is still alive, but Simon's not sure how to safely wake him up or what to do if that starts to change. He decides to just keep an eye on the situation, presumably there's a system that will wake the guy up whenever the ship reaches its destination, and if he starts to look bad before that point then Simon can always try to manually revive him and hope for the best.
Anyway, the ship has medicine and supplies, which he desperately needs. He figures the other two crewmen weren't planning on dying, so they can probably spare enough of said supplies for him. He figures out the AI well enough to start asking questions and eventually puts together that he's time traveled(?) or crossed into another dimension, that this ship is on a mission to figure out why the stars are going dim, or rather why there's one star that isn't, and he's not sure what to make of it but it seems he's also landed on another one-way trip.
When Grace wakes up, confused and without his memories, Simon panics and because Grace assumes he must've been part of the crew he just... goes with that. Grace thinks that he woke up from stasis early and that his weirdness is a result of isolation. He's a little surprised that there's an amputee aboard but it would be insensitive to ask, right? Not that a one-armed guy can't be an astronaut, yeah? Although Simon is also weirdly cagey about what his specialty is supposed to be and seems vague on the mission too, Grace assumes his memory also suffered some kind of an issue from being in stasis, he's just glad he's not alone.
Then they run into Blip-A and they're even more not alone, Rocky moves in, everyone does science, Simon still doesn't really seem to have an area of expertise per se, Grace keeps waiting to remember the part where Simon joined the mission (he's sure he'd remember him), Simon's kind of sweating bullets still wondering how he's supposed to explain anything, and then the whole fishing trip on Adrian goes pear-shaped and Simon uses like. Eldritch blood magic...?
Grace is having trouble computing that but he definitely saw it. So. Guess that explains why he's on the mission, if someone found a literal space wizard they would want them on the Mankind-saving mission, if ever there was a time for some kind of secret cult society of wizards living under the radar to come out in the open it would be now, yeah. But Grace can also see where explaining that to an amnesiac would be awkward and seem too hard to believe.
He has connected the dots!
Anyway he doesn't really notice that his Simon Joins the Mission and Reveals Wizards memories never arrive, he's too distracted by the revelation that Stratt forced him to go on the mission and he didn't volunteer, and then there's the whole issue with the taumoeba breaking containment and turning back to rescue Rocky and save Erid, which they both agree to do. By that point Simon has established himself as a presence in Grace's mind and Grace no longer considers him that much of a mystery to be solved (Simon's abilities are, Simon himself is not), whenever Simon lets slip something about like, competing for food or being in prison or in a cult, Grace just assumes he himself was pretty sheltered from how bad the situation on Earth was getting due to being in the Project Hail Mary bubble, and is like yeah okay Stratt double fair play to you, I didn't realize it was getting quite so Mad Max out there.
Now up until this point, Simon has done a good job of staying out of Grace's logs. Grace has mentioned him but in such a way that everyone on Earth probably thinks he's hallucinated an imaginary friend in the isolation and stress, like well damn he's cracked but at least the science seems sound.
Yes sure Dr Ryland Grace, your good friend Simon the One-Armed Blood Wizard is up there with you and the aliens, and for that matter so are all of us in spirit. Godspeed and thank you for your noble sacrifice.
Grace himself thinks that Simon is making his own reports, but when they go to send the beetles he's like, no we should do one together to make it clear that we're both agreeing to this and have come to this decision as a team. At which point Simon is just like, well... okay? Still just kind of avoiding conflict by going with the path of least resistance. So he smiles and nods and waves at the camera, and is like Hello Earth, Simon the One-Armed Blood Wizard here. Um. Yeah I'm good with going back to save Rocky and Erid too. Best wishes, and all that.
Grace doesn't find out until they're on Erid and they get the first long distance transmission from Earth that essentially amounts to him discovering that not only did he make first contact with aliens, he also made first contact with interdimensional blood wizards.
