Doctor Who: Peter Capaldi’s 12 Greatest Moments As The Doctor

11) How Did The Half-Face Man Die?

When the Twelfth Doctor properly entered the show in time for 2014’s season 8, it quickly became clear that he was a very different man from his predecessors. Gone was the youth and affability, and in their place were crankiness and a much darker personality.

The best example of this came in “Deep Breath,” when the Doctor confronts the villain-of-the-week, the so-called Half-Face Man – a very old android which has kept itself operational with human transplants. For the Doctor’s friends to be saved, the Half-Face Man needs to die. And he does, as he ends up impaled on the spire atop Big Ben. But how did that happen? Did the android give into its guilt? Or did the Doctor break his “basic programming” and commit murder?

It’s a brilliantly dramatic scene and one that fans will likely be debating forever.