Every Doctor Who Christmas Special Ranked From Worst To Best

Last Christmas is one of Doctor Who's typical "base under siege" stories, but with a twist: the Doctor and Clara have to figure out what's real, and what's a dream. Cue a dark, twisty-turny tale that's layered with seasonal cheer, horror, and the pensiveness we all tend to feel at this time of year, an episode in which nobody - not even the Doctor - is ever fully sure what's real.

Overall, it's fantastic stuff, with highlights such as Nick Frost's hilarious turn as Banter Claus, the chilling - albeit derivative - design of the aliens themselves, and a touching final scene between Twelve and old Clara that smartly echoes her treatment of an aged Doctor in the previous year's Christmas special, The Time Of The Doctor.

The episode isn't without its issues though. Since it's obvious that the entire thing is a dream from the beginning, the tension never quite hits that edge-of-your-seat degree, and the plot starts to fizzle out the longer it goes on. It's also not particularly inventive, cribbing from the likes of Alien (which, to be fair, Moffat's script does acknowledge), Inception, and even itself, with Series 5 episode Amy's Choice carrying a suspiciously similar dream-centric concept.

But taken as a whole, everything clicks together brilliantly, resulting in a ride that's equal parts thrilling, scary, and funny. It's a balancing act that Moffat capably pulls off, proving that even potentially tired ideas, when injected with enough energy, can land with a big bang.