"I think we're from two different Earths. Mine didn't have shuttles you could leave on. No one got out before...our big disaster. Disease, no cure, 100% fatality rate. Wiped out most of the world's population. Only a handful of random people were immune."

Something like one percent of the population. Nadine wonders what happened to his Earth, to necessitate leaving the planet. And at the fact that was even possible.

"What year was it for you? I've met some people from different times. I'm from 2020."

This sort of stuff has suddenly become important to specify.