No words can describe this.
Remember Moffat wrote this episode. Moffat. The guy everyone seems to hate, wrote this gem of an episode.
This was before he was put in charge though. He wrote this when he had certain guidelines to follow and it was a fantastic episode. If you put this episode in front of me and then put on Asylum of the Daleks before I’d started watching the show, I would never have thought they were written by the same person.