She couldn't hide her disappointment, either. They were going to end up clutching at straws again, she could tell. Everything they knew - or thought that they knew - was based on guesswork.

"They've taken other species, not just humans. And we're all from different universes."

If you wanted to prevent the extinction of a species, you didn't want to mix genetic lines like that. She couldn't begin to guess at the differences that had evolved over time and across space.