Re: 7X12 Nightmare in Silver(Grading/Discussion)(SPOILERS)
I might have missed it since the episode wasn't interesting to me but is it explained how the Cybermen were able to upgrade to the super speedy type?
"It's not that you can see the strings, it's that 40 years later you're still looking at them." - Steven Moffat
"This movie was big. Imagine how big it could have been with me in it?" William Shatner