Doctor Who: Every Doctor's DEFINITIVE Episode

4. Heaven Sent (The Twelfth Doctor)

...aaaaaaaand absolutely no-one was shocked.

45 minutes of Peter Capaldi running around a castle and talking to himself is somehow Doctor Who at its absolute peak, stripping both the essence of the show and the character of the Doctor down to their cores. Peter Capaldi gives the performance of his career, carrying an entire episode that channels grief, rage, humour, intellect and despair without ever losing momentum.

The Doctor is trapped inside, "a killer puzzle box designed to scare him to death" – possibly the most Doctor-suited scenario we've ever seen. We get to see him as a problem-solver in a way that's rarely seen in the show, a storyteller, and a grief-stricken and very human man grappling with the death of his favourite person in existence. Without any companions to show off to, or a villain to posture against, we get to see the Doctor as he is when he's truly alone, and this allows Capaldi to channel an exceedingly rare streak of vulnerability.

It feels like every version of the character exists is this story. The genius, the action hero, the chessmaster, the stubborn old man, the one who hides his grief and the one who wears it on his sleeve – everyone's invited. Beat that for definitive.

Moody, spooky, and tinged with melancholy, Heaven Sent is the sort of Doctor Who episode that Peter Capaldi's casting enabled. His skills as an actor elevated the show, and Heaven Sent absolutely nails it.

Much like The Caves of Androzani, you wouldn't want Doctor Who to be like this every week, but you're amazed that the show has something like Heaven Sent in its wheelhouse.