So Carver's a Grey Warden... Nathaniel's hesitant to bring up Bethany, and how she's the one who is a Grey Warden. But he's convinced now that, although this man may be Hawke, he's not the Hawke that Nathaniel knows.

"No, he's not in trouble." Nathaniel is definitely skirting the subject of Carver now. But there are certain things he should perhaps share.

"Time works a little strangely here. As does... reality." Maker, this feels strange to explain. "There are several people from Thedas here. All of us are from the same world, but different times within that world. And some of us are from different... realities."

There, that should explain everything.