The TARDIS lands in a petrified forest on an alien planet. Determined to explore, the Doctor leads his companions into the metal city, where they discover the danger of what will become his deadliest enemies, the mutant Daleks. (Originally broadcast in seven parts.) Written by
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This episode was watched by 6.9 million viewers on its original transmission. See more
Early in the episode, the studio backcloth moves from the effect of a wind machine. See more
Well, I suggest before we go outside and explore, let us clean ourselves up.
Now, what does the radiation read, Susan?
It's reading normal, Grandfather.
[after she turns away, the radiation dial switches across to read 'Danger'