Twice Upon A Time

This episode is the end of a Doctor Who era. Peter Capaldi's last as the Doctor and Steven Moffat's last as showrunner.

The episode opens with a 'previously' that only Doctor Who could get away with, looking back to 1966. Suddenly grainy footage of William Hartnell's First Doctor turns into high quality footage of David Bradley as the same character.

The episode sees the Twelfth and the First Doctors, both refusing to regenerate, bumping into a Captain from the First World War. He's been removed from time by the Testimony whose intentions are unclear.

The cast are superb here- Capaldi is such a great Doctor who I fear has been underated by much of the audience and he's at his best here. David Bradley is also brilliant as the First Doctor- if you weren't quite paying attention you might think the  BBC had resurrected William Hartnell.

There's also fantastic writing, Steven Moffat's last on the show. It's everything a good episode of Doctor Who should be- really funny, exciting and emotional. He plays with Doctor Who lore well and let's Capaldi's final speech be like a greatest hits speech from his time as showrunner.

The episode ends with Jodie Whittaker making her first appearance as the Doctor. Suffice to say she is immediately brilliant.

I think this is Steven Moffat's best Christmas episode and right up there with his best. A fitting end for the Twelfth Doctor.