Oh my _gosh_...!
From Wikipedia:
"The final story of Season 11 (entitled The Final Game) was originally intended to write out the character of the Master, with the villainous Time Lord sacrificing his life to save the Doctor's. Due to the tragic death of actor Roger Delgado, script editor Terrance Dicks abandoned the project in favour of a new story, which eventually evolved into Planet of the Spiders."
Wow.
Also, I like how Sarah Jane became a Skittles commercial there for a moment.
Also also, "Fires of Pompeii"!!
But I'm still incredibly sad about the whole Delgado thing...
"The final story of Season 11 (entitled The Final Game) was originally intended to write out the character of the Master, with the villainous Time Lord sacrificing his life to save the Doctor's. Due to the tragic death of actor Roger Delgado, script editor Terrance Dicks abandoned the project in favour of a new story, which eventually evolved into Planet of the Spiders."
Wow.
Also, I like how Sarah Jane became a Skittles commercial there for a moment.
Also also, "Fires of Pompeii"!!
But I'm still incredibly sad about the whole Delgado thing...