[Gogan]

Ahh, thanks for the clarification all. I figured there was a ton of backstory that we just don't get on the show. One of the drawbacks of trying to condense such an immense story into 10 episodes per season, I guess.

We've only seen small bits of the white walkers so far, and while I get that they're not terribly friendly creatures, the show really hasn't shown us what a big threat they really are. Certainly not a big enough threat to send all of the wildlings fleeing south. I assume we'll be seeing much more of them later.

Didn't know the tunnels at the other castles were filled with ice. That makes a lot more sense now too.