The sad, horrible fact of the matter is, Grace was never going to go home. He was never going to see his classroom again.
Even if everything had gone right. Even if Dubois and Shapiro had survived. Even if the mission went off without a hitch.
He was Stratt's right hand man. He was there for the bombing of Antarctica, the paving of the Sahara, and each and every terrible, terrible choice they were forced to do. He saw all of it, and at points was absolutely complicit. He even begged to be allowed to continue to work on the project.
If he had not gone on the Hail Mary, not been cemented in history as a hero (and later on, once the truth comes out, the sacrificial lamb), he would have been condemned right next to Stratt.
In the end, his ignorance was always his fatal flaw.
