I.M.POSTER

All their life Red was looked at like a walking warning sign, to be avoided by all in public and shunned out from society. When the end of the world arises, and twelve highly trained astronauts are mankind's last hope, they're given the first chance in their lifetime to prove to humanity that they can be a good person. The only issue is, someone is trying to sabotage Mission Proxima B. It seems there is an I.M.POSTER onboard the ship, and everyone is suspecting them. It's up to Red and them alone to expose the traitor, save their crewmates, complete Alpha Centauri, and get this half-assed shuttle straight to Polus, no matter how long it takes them.
Even if they die trying.
Or
An among us fanfic, but this time, Red isn't the imposter.