Simon told Grace about being in the sub and the monster and the blood. He did not tell Grace why he was there. He's desperate to leave the convict and the butcher behind him. Grace saved him. He's kind and forgiving and saved the stars. He's better than Simon deserves, and he knows it, but Simon nearly died in the most horrific way possible, and it's been like a year in the biodome on Erid, and he's happy.
And then the same thing that brought him to Erid drags a COI ship to Erid as well. And Simon's terrified and grieving. He knows that Grace is going to find out and won't look at him with care anymore. He'll know how terrible Simon is.
But that's not what happens.
See, when Grace hears the real story, and the people in the COI start getting pissy that the convict is living in such luxury, Grace gives them a dead eyed look and says: "You promised him freedom if he went into the ship. He did. He survived. He's paid for his crimes."
Because, while Simon doesn't remember it, the very first thing out of his mouth when he woke in a panic was "They promised me my freedom if I went into the ship!" So while Grace didn't know what Simon did to earn what was clearly a suicide mission, he knew it was bad. And he knew Simon was cleared. They'd talked about their missions. Grace knew what he did. Simon was like him.
And that's when it becomes a problem for the COI. What the higher-ups would *like* to do is move into the biodome, take control, and have a new place for humanity (or at least the humanity on the ship). But it becomes clear very rapidly that they cannot remove Dr. Ryland Grace and make a new leader. If anything happens to Grace, the COI will be lucky if the Eridians simply blow up their spaceship.
Dr. Ryland Grace is very special to the Eridians. He saved the stars, and more than that, he gave up a chance to go home to return one of their own safely to Erid. He put Eridians above himself. He was kind to his own detriment. And from the human movies, shows, and books, they know that humans are not always like that.
When it comes to other humans, the Eridians defer to Grace. And if Grace, who is kind and forgiving and caring, looks at humans with eyes filled with anger, then the Eridians know they are not humans worth keeping.
So the COI gets three choices:
1) They can submit, move in to the biodome, and follow the rules, knowing that as far as laws, Grace isn't a president, king or emperor, he's a god and what he says goes.
2) The Eridians will get them food and fuel and point them in the direction of earth, and they can *hope* they make it.
3) If they refuse to be peaceful about staying or leaving, the Eridians will drop them into Erid without protective gear and let them "survive on their own" far away from the biodome so Grace and Simon won't be bothered.
A few choose to stay. A few choose to leave. And a couple of the more belligerent, unfortunately for them, choose 3.
And Simon? Simon finds himself in a weird position of respect, because he's important to Grace, and he's been working to help Rocky and Erid's scientists just like Grace.
But most of all, he's never felt so safe and protected. Because no one with that much power has ever protected him.
And Grace, for his part, is a bit uncomfortable for having to acknowledge the power he has on Erid, but he doesn't mind because it keeps Simon and the new biodome residents safe.