Found in the back of a cab in Cardiff. Image posted to Facebook with the line "found Dr Who script in the back of a taxi. Cheeky spoilers anyone?" before being posted to Reddit.
The finder did try to get in touch with the BBC and the production team to return the script without joy, though after the Reddit posting, things took a natural turn and arrangements were made.
We can of course note that Jenna-Louise Coleman's character is called Clara, Being Human's Jason Watkins is in this episode, and so is Warwick Davies, playing "Porridge". Indeed, Warwick tweeted:
Just finished my first day's filming on #DrWho. It's been my ambition for years. And to top it all – there are Cybermen in this episode!
— Warwick Davis (@WarwickADavis) November 7, 2012
And of course there is Eve De Leon Allen, a young actress, better known for playing "The Boss" in my youngest daughter's much loved show, Nuzzle And Scratch.