Doctor Who: All 40 Steven Moffat Episodes Ranked From Worst To Best

Although the hologrammatic reindeer antlers fail to give the Doctor any festive cheer (oh TARDIS, what are you like?), Moffat delivers his best Christmas special full of bounce, knowing and suggestive repartee, and a dash of sweetie.

The Doctor is a dab hand at emotionally-charged speeches, but the one where he inveighs at King Hydroflax's (played by the naturally funny Greg Davies) oppressive rule doesn't have the usually desired effect and instead falls, hilariously, flat. We get to see the Doctor exhibit his newfound cross arms, making a lovely addition to his cross eyebrows.

The funniest moment has to be when the Doctor finally gets his go at the whole "it's bigger on the inside" trope. This is Capaldi playing his 15-year-old self: the lifelong fan who wrote that letter in 1974 now having all of his wildest dreams come true in entering the TARDIS.

Kingston enthused about Capaldi: "He’s just so funny with the faces he pulls on-screen. He’s one of those actors that when you’re actually working next to him you don’t actually see it. He’s brilliant to watch."

You could turn this episode into a drinking game given the amount of times the Doctor heavily infers to River of who he actually is.

The comedy is allied to poignancy as we become aware that River's story is about to come full circle (sonic screwdriver, spoilers an’ all). Capaldi and Kingston radiate instant and natural chemistry in a single hour, so 24 years on Darillium... ahem! That new suit and haircut clearly worked wonders.