Yeah, I kept saying through the whole episode, "What is so terrible on the other side of the wall??" They mentioned it early on in the show (I think) but we've never learned why the wall is there. I've read enough scifi and fanfic AUs to think that generally, the people inside the wall are either bad or deluded, and the good rebels are outside. Maybe this will be different?

Also, when someone mentioned that they had built a whole bunch of DRNs that were just left after the contract was awarded to another company, and then Nigel mentioned it AGAIN, I knew something was going on. He wants to continue his work!