he opening credits of this epic anniversary blowout had to create a big impact, opening as it did a story that marked the programme’s half century. Writer Steven Moffat came up with just the thing – the TARDIS being suspended over Trafalgar Square, and Matt Smith’s sorely-missed Gallifreyan dangling from the base.

This famous location turned out to be a mere jumping off point for the story, as bolshy relative Kate Lethbridge-Stewart and still-alive assistant Osgood emerged to brief the Time Lord and Clara about the forthcoming rollercaster ride of living paintings, barnacled shape-shifters and serial-shagging predecessors.