"Why this city? Understand that I am charged with the protection of Portet, so the appearance of other planar creatures and the wolves chasing them is concerning. So forgive me for all of these questions and my apprehension. Do you target females of any race? Can you give me the names of any you have taken from Portet so far? I think this all may have been a misunderstanding and we might be able to let you go with all of your possessions, but I need to be certain there is no threat here."
Sense Motive total 23 to get a feel for why he is talking the way he is.
Is impersonating a human while being a planar creature a crime?
How about taking a willing person to another plane?
What age would a person have to be according to the laws of Icefia to consent to such a thing?
After he answers this round of questions, I say, "I think your bucket should be ready, I will be right back."
Once outside the room, "Does anyone know anything about the other planes or a portal to the plane of water?" I describe what he has said so far and ask anyone if they have any thoughts on where to take the questioning next.