Willa, unfortunately, has a very confused viking vampire on her hands. Clearly she knows him, which if he's just going on gut feelings, he would assume she knows him very well.
"You've been sentenced to prison. However, it's incredibly likely that it's temporary for you. They're able to take people from different time periods." Which he would guess is what is happening here.
"And I'm going to take a wild guess that you're from my future as I've been here several months and up until this moment, I would have said the only vampire I have ever made was Pam, so you're going to have to bear with me and I do apologize," he actually sounds sincere about that, 'but who the fuck are you?"