"The United States. Earth. Yes, I've been. Not recently." And that's recently by Jack's very skewed standards, which would be lifetimes for anyone else. Still, it doesn't really matter how long it's been, Jack is fairly certain he'd have heard about a leap in human evolution like this one, even if he was only passing through the time. He's been to the end of the universe and back, but this kid is something new. Or, far more likely, something alien. "Is that where you're from? Where you were born? Earth?"

The fact that they're still flinging themselves from building to building doesn't seem to phase Jack much. They might as well be having this conversation on the ground. Once you've rocketed through time and space clinging to the outside of a TARDIS, damn near all other modes of transportation seem tame. Or, in the case of this one, fun. More fun than he's had in the last couple of days, at least. "I'm Jack, by the way. Never did introduce ourselves, did we? Captain Jack Harkness."