Underrated book moment is just after Grace shows up to rescue Rocky and he tells him that he's gonna die of starvation probably shortly after they reach Erid, and Rocky's response is:
“Then you go home. Go home now. I wait here. Erid maybe send another ship someday.”
“That's ridiculous. Do you really want to risk the survival of your entire species on that guess?”
He's silent for a few moments and finally answers. “No.”
Like holy shit.
Until Grace showed up, Rocky was gonna die. Rocky was gonna die of radiation poisoning, a horrible death that he watched his whole crew already succumb to, because the astrophage was not only his only fuel but also his only protection from radiation.
If the Eridians were gonna send another ship, they'd probably have sent it forty years ago.
Furthermore, if the Eridians sent another ship, it would almost certainly be made of xenonite, because everything they make is made of xenonite, which means that a) most of the crew would die of radiation poisoning and b) whoever survived would end up in the exact same situation as Rocky, because the taumoeba would escape into their ship the moment they docked and start gobbling up all their delicious fuel.
And still, Rocky gives Grace the chance to leave. Kind of like Yao did.
“Yeah, of course I want you to stay, but you can go. You can go home, and you can live, and I will lie to make you feel like that choice is one that won't kill me and everyone I love, because you deserve to be allowed to live if you want.”
Grace has to be in the Stratt role here. Grace has to be the one explaining that he's made the cold calculations, that he's aware of the consequences and that he's making this decision anyway because it's the only decision he can make. This is the only decision that will save their worlds.
Grace has to be the one to convince Rocky to let him die for Earth and Erid.
And yeah obviously it all works out because of the power of friendship/taumoeba, but this is where Grace earns his happy ending. Grace has to stand on the other side of that desk, watch somebody else beg for his (Grace's) life, and say “no, this has to happen, because it's the only thing that can happen.”
(Rocky, meanwhile, 100% threatens to throw the taumoeba out the airlock when they get to Erid unless the Eridian governments immediately learn how to synthesise vitamin C.)
