- You may be looking for the real world television story.
The Dark Dimension was the intended 30th Anniversary episode of Doctor Who.
It ceased production in 1993 after an argument broke out over the size of Tom Baker's part. (COMIC: Doctor Whoah! 379 [+]Baxter, Doctor Whoah! stories (Panini Comics, 2007).)
Colin Baker had the episode's script stored in his shed. (COMIC: Doctor Whoah! 448 [+]Baxter, Doctor Whoah! stories (Panini Comics, 2012).)