[Maggie squeezes his hand reassuringly to reaffirm she is not letting go. She's not sure what they'll find outside, but it's likely something both of them are better off not facing alone.]

Don't worry, I've got you. We're in this together now.

[There's a pause as the realization sinks in that she's essentially just dumped on him that there's been more than one world war. She takes a deep breath and nods before continuing.]

Yeah. There was a second one, about... twenty years after the end of the first one, if I remember my history classes right. A lot's changed since then - but that probably goes without saying.