I think it’s a great episode,” he said. “It’s really quite scary – it’s one of the scariest ones we’ve done, but it’s also one of the happiest.

Santa appears on Clara Oswald’s roof with his elves, but what might otherwise be an excuse for cheer and happiness is actually a nightmarish development – and only the Doctor knows why!

He has to arrive and save her from what Santa’s going to bring into her life. The Doctor’s slightly competitive with other semi-mythical characters!