Peter Capaldi, Steven Moffat and Michelle Gomez talk about the casting of Missy as the Master.

“It’s just a proper good old twist. We’ve been saying for years now, certainly since I took over, that regeneration can change your gender and that I thought is maybe the one they won’t see coming.” – Steven Moffat

‘Doctor Who’ Series 8 finale airs today on BBC One at 7:30pm and on BBC America on Saturdays at 9pm.