A female sentient concrete disguised as the Chiswick flyover (TV: The Nightmare Man) telepathically controlled people. Sarah Jane Smith and her friends defeated and destroyed it, with only part of the sentient concrete remaining. (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)
The part of the sentient concrete that was used to control the minds of people. (TV: The Nightmare Man)