The creepy ship in the underground tunnel. Did the control room look an awful lot like the control room of the ship in the Something-or-other-Lodger (can't remember the actual ep title right now, but the one where the TARDIS won't land and the Doctor has to pretend to be a Regular Bloke and moves in with the useless guy whose girlfriend wants to work with monkeys and There Is No Second Floor and the cat knew it all along and the alien ship was just trying to find a pilot but kept killing people by accident - you know the one)? I am thinking mainly of the big creepy spider-leg pillar things and the control panels with the big globes on it. I would go back and compare, but haven't actually downloaded it yet so can't rewind and look again.
Again, I am probably imagining it. Was just wondering if the similarity struck anyone else.