The children in gas masks were back. If they weren't so creepy I'd feel sorry for it. I did feel sorry for it. At least the Doctor and Jack were there...made it a little less creepy.
Don't worry, it wasn't really a little kid with a gas mask. It was some type of alien robot. Nano genes I think? They were just trying to help but got the wrong information.
For something that started as a scary movie, it turned out to be a happy ending. Everyone lived and the Doctor danced! It was fantastic!