The Doctor and Clara face their Last Christmas. Trapped on an Arctic base, under attack from terrifying creatures, who are you going to call? Santa Claus!

The Doctor has retired to 1892 London. Despite the protests of his allies, he is determined to keep out of mankind's affairs. However, a governess named Clara has stumbled upon a plot which only the Doctor can unravel, involving the death of her predecessor in ice and the sinister Dr. Simeon, who controls monsters made of sentient snow. And there is another mystery afoot: Clara is the spitting image of Oswin Oswald, whom the Doctor saw die in the Dalek asylum...

Through a series of unfortunate events, three mummies end up in present-day London and embark on a wacky and hilarious journey in search of an old ring belonging to the Royal Family, stolen by ambitious archaeologist Lord Carnaby.