Factual error: The Viking village has tubs of electric eels in the boathouse, which prove instrumental to the plot as the power source of the makeshift electromagnet used to relieve several of the attacking aliens of their helmets. The problem is that the Vikings live somewhere in northern Europe, and this episode takes place in the 800s. Electric eels are native to the Amazon and Orinoco rivers of South America, which at this point in history no one in Europe knew existed.
Doctor Who (2005)
1 factual error in The Girl Who Died
Continuity mistake: Before Martha uses Project Indigo, she doesn't have an ear piece. Then, after two quick shots of Daleks, when Martha says, "Bye, Jack," she does (and then takes it out). (00:17:56)
The Doctor: I'm not... I'm not... I'm not from Mars!
Rise of the Cybermen (1) - S2-E8
Trivia: Only eleven Cybermen costumes were built, but careful filming made it look as if there were more.
Last of the Time Lords (3) - S3-E13
Question: Why does The Master fear The Doctor forgiving him? What's he forgiving The Master for exactly?
Chosen answer: The Master knows that deep down, he deserves death for the crimes that he's committed throughout his life, and since he regards The Doctor as his arch-foe, he expects it to be at his hands. The fact that The Doctor is still willing to forgive him after everything the Master's put him through hurts him more deeply than death would.
Captain Defenestrator