Like Percy's vial of so-called truth potion, she knows that no matter what the danger might be in taking it, there's worse danger in being seen to resist taking it.

"Of course," she whispers. "Thank you. Will I ... please, will I be able to use my arm again?"

And she looks up, eyes wide and teary, with all the genuine fear she's feeling -- and none of the cold calculation that's there as well.