This week's Doctor Who brought new meaning to the phrase "it's bigger on the inside" as the Doctor was trapped in a dimensionally-sapped tiny Tardis and Clara was pursued by 2D monsters.

Luckily Clara managed to keep her wits about her, see a solution and save the day – but were you paying as much attention?

Take our quiz and find out – it adds whole new dimensions to the idea of TV-watching...

Buy the series 8 DVD or Blu-ray from the BBC shop and get an exclusive TARDIS sound chip and FREE artcards