Nate felt incredibly guilty, he knew this was all his fault, his desire to do something to be something. He had almost, almost, asked to come back with Vance and the others. In a way it was easier. He'd be busy, he'd have a purpose - even if it was one he wasn't too fond of - but one where he felt in some way needed. There was also the chance of returning to the dimension which held the one person in the world, in any world, who could help him cope. However, even if they did find the right dimension to return to, chances were high he'd never see Sophie again. In a way he knew he wouldn't. When they returned it would be the same life, the same prison, as they had here - and returning meant never seeing Eliot again, never being in contact with him again.
He was too selfish a man to give up the one family he did have, even if their predicament were caused by his restlessness.
"Don't be angry with April," Nate said. "She's done nothing to deserve it. If we'd done what she told us to in the first place, we wouldn't be in this mess. I got both of you into this, and all three of us know it."
He didn't worry too much about his job, he truly didn't care about it. He disliked this life with a passion, and the only reason he stayed was Eliot. He now knew that wasn't an option either. He'd help them get to wherever they decided and help them get settled and prepare for Eve's birth, but once that was done, he needed to find his own way - and more importantly, to stay out of theirs.