Doctor Who: 20 Things You Didn't Know About Heaven Sent
5. It Could Have Been A Big Finish Story
God bless Big Finish Productions.
This company has been making excellent Doctor Who audio dramas since 1999, helping to fill in the gaps and provide a time-travelling fix when the show is off the air.
Though there's no visual element, Big Finish stories can be just as compelling as those that play out on TV. And in an alternate reality, we would've got an audio-only version of Heaven Sent!
Moffat originally dreamt up the idea of the transmat (the thing that makes clones of the Doctor) for a Big Finish story he was considering submitting in the late '90s.
But of course, this never happened, and he held on to the idea until 2015 instead.