The series is catapulted back into the urban scrub of the Eccleston days, and promptly starts scrambling around for it's earthy magic, although graffiti monsters will do for the time being.
If you're going to succumb to the urge to make every throwaway reference into a full-blown story, this is probably the way to do it.
In the 'Doctor Who' universe it's canonical that Earth had a twin planet and Vikings had horned helmets. Scientific realism left the building a long time ago.
Spare a thought for the middle episodes, doomed as they are to be half-remembered, cast aside and left out of your end of year rankings.
Sometimes the best episodes of television happen when you run out of time and money and have to make an adventure where half the regular cast fight an invisible alien on one set whilst spit-balling philosophy. Beats the 'Fantastic Voyage' episode, anyway.
An episode of "Doctor Who" from 1976 that fell through a wormhole and ended up in 2014.
In 'Doctor Who', the story where the Doctor falls over and morphs into another actor is only as good as the next episode, where that actor has to wear someone else's clothes and act a bit loopy. How did it go last time round?