Grinding his teeth, Atram spoke up in challenge.
"So? You think surprising us for a moment is enough to make us stop?"
"Oh, stop bluffing," Touko waved Atram off, a bitter smile on her face. "Magecraft is
made up of the belief one can enact change in the world, and concentration sufficient
to actualize that change. Even closing my eyes makes the image of that face reappear in 
my mind. I doubt I'd be up to using anything above Cause level magecraft for two or
three hours."
Touko bluntly explained her own situation. Though it felt like the kind of thing that
should have been fatal just to hear, this woman just dropped it like it was nothing,
without even a hint of bravado.

The Case Files of Lord El-Melloi II, Volume 3, Chapter 2, Part 6