Doctor Who: The Best Episodes From Each Modern Series

"Some days... all the windows align and everything seems to work, and you think: this episode's a cracker."

We could use Steven Moffat's own words to sum up this breathtaking episode. However it's more of a pleasure waxing lyrical about Heaven Sent for ages, but perhaps not for 4.5 billion years.

Everything really did align here. Moffat's gorgeously enigmatic script, which included the welcoming version of the Doctor's own mind palace, and this gem of a brilliantly funny in-joke: "I've finally run out of corridor. There's a life summed up." Rachel Talalay's arresting and artful direction - making the torturously thudding Veil as menacing as the Terminator, and Principal Skinner chasing Bart Simpson. The satisfying sprinkling of some classic foreboding Doctor Who synth, and the rousing crescendo when the Doctor finally breaks through the tough son of a bitch Azbantium wall. Oh Rassilon, you've done it now.

Out of the many mesmerisingly mind-bending performances from Peter Capaldi, Heaven Sent is his magnum opus - enthralling an audience alone. Think Tom Hanks in Cast Away, Will Smith in I Am Legend, Sam Rockwell in Moon, and Sandra Bullock in Gravity. Yes, that good. Oh and the quick glance to the camera in his "storm room" is a delightfully deft touch.

This is the Doctor fuelled by incandescent and unforgiving rage. Scared yet heartbreakingly resolute after billions of brutal, burnt and bloody years painstakingly punching his way out of the Time Lord’s version of Fort Boyard. That's a hell of a bird. It's one hell of an episode.