Tony didn't know what it was about him, where he felt like every weight that showed up needed to be rested on his shoulders, but he did. And this was just another one, maybe. If he hadn't stepped through the door when he had, would this have not happened at all? Had he triggered this somehow?
It'd never happened before, finding someone they knew. But Tony knew that the only course of action would be to bring her back with him. Because he wasn't going to let Nebula just say here in the nothing. He was just so tired of losing people.
"One way trip to Starklandia," he said after a moment of staring out at where a city wasn't. "I'm sorry." Because she'd just given something up too, just lost her own people. And that felt bad.