I really enjoyed this year Dr Who Christmas special. It was pretty clever stuff. The main enemy was something called the General Intelligence. There was a reference to the London underground, which made no sense to me. When I read the guardian review, I found out that the snowmen had featured in two earlier Dr Who episodes:The Abominable Snowmen and the web of fear first shown in the late 60s.
Obviously I had to watch the earlier Dr Who episodes, but Itunes doesn't sell many of the first few series of Dr Who. According to wikipedia 5 out of 6 episodes of the web of fear are missing, because the BBC used to wipe earlier episodes. So now people are referencing Dr Who episodes that are lost. How did Moffat use a lost TV episode as the back theme for the 2012 Christmas special? Perhaps the general intelligence is real and they stole the Dr Who show.
Perhaps he watched a fan reconstruction on Youtube. I have also ordered the novel.