And then he heard Mad-Eye Moody's voice, echoing in some distant chamber of his...

And then he heard Mad-Eye Moody's voice, echoing in some distant chamber of his empty brain: Harry bent his knees obediently, preparing to spring.
Why, though? Another voice had awoken in the back of his brain.
Stupid thing to do, really, said the voice.
No, I don't think I will, thanks, said the other voice, a little more firmly . . . no, I don't really want to . . . NOW!
The next thing Harry felt was considerable pain. He had both jumped and tried to prevent himself from jumping - the result was that he'd smashed headlong into the desk, knocking it over, and, by the feeling in his legs, fractured both his kneecaps.