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 Unbound Doctors [Big Finish]
for The Unbound Doctors [Big Finish] in Doctor Who: The Different Who 2
Suggested by doctorwho2000s
What will happen if: The Fourth Doctor's tenure, was short?