Use this as a tool for your locked and private stories to cover up major reveals or plot twists. Also Use It To Make It Mean You Can't Find The Person For The Role.
Spoiler
The Other
for The Other in Doctor Who: Season 30 (1993)
Suggested by ringothedrummer
What if Doctor Who wasn't cancelled and continued? This focuses on what could have been season 30, before the 30th Anniversary Special.