Doctor Who: Peter Capaldi’s 9 Coolest Stand Alone Episodes

This Capaldi sign-off was a heartfelt bow-out, twice fold. By all rights, the 12th Doctor's run should have ended during the explosive finale of The Doctor Falls. He was even primed to regenerate. Instead, we were treated to one final aftermath episode which was an eclectic blend of nothing and everything.

It was 'nothing' in the sense that there was no villainous force, only a celestial work of good. The entire episode was centred around The Doctor's struggle to come to terms with the prospect of moving on and changing for the better, both in his 12th incarnation and in his first.

It was 'everything' in terms of substance. Set in a poignant World War 1 backdrop, and featuring Steven Moffat's long-term collaborator Mark Gatiss, the episode brought a stellar trio of performances, from Gatiss, Capaldi, and the amazing David Bradley as William Hartnell's iconic first Doctor.

To this day, nobody quite knows what Capaldi is babbling on about in his regeneration scene, but the episode itself was a wonderful goodbye to both Peter Capaldi and Steven Moffat, plus a cool swift intro to Jodie Whittaker.