Sentient concrete
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A female sentient concrete disguised as the Chiswick flyover (TV: The Nightmare Man) telepathically controled people. Sarah Jane Smith and her friends defeated the sentient concrete. It was destroyed. Only the part of the sentient concrete remained that was used to control people's mind. (PROSE: The Nightmare Man) Sarah Jane Smith kept that part inside her attic. K9 later used it to talk to Luke Smith when Luke was caught in a nightmare of the Nightmare Man. (TV: The Nightmare Man)