4. The Girl In The Fireplace
Clockwork is spooky, when you think about it. It's the most basic form of software, in a way: mechanics that work on their own, without interference, imitating something like life. So it's no surprise that a clockwork person turns out really frightening. The French court mock-up makes it even worse. When you think about it, the effect should be to make them less scary: clown masks under wigs and coattails are not exactly intimidating when worn by anyone else--the opposite, in fact. But it makes them more scary, as the whirr and spin with empty eye-holes. Every character but the Doctor is cornered by these things, and their stiff movents and black eyes are ridiculously creepy. They speak in jerks, without moving their lips--you know there's nothing under that mask that is anything like a face. And I must say, the moment when the Doctor is almost grabbed by one under the bed makes me yelp every time.