Her saying that she's from the future has Jake stopping mid-step. That was a bit more messed up than he'd like to admit. 2149. That was a good... well, it was way too far into the future. After a moment, he starts following her again.
"They're not that hard to use, if you have the right teacher," he tells her before looking where she was pointing with the envelope. "Outside doesn't look so bad." Didn't mean that the inside would look fine. "So, where you're from Earth was destroyed... By a nuclear fall out. Sounds pretty messed up."