16. What is Margeurite's first response to Chauvelin's request of her?

Margurete is mortified that her brother's life depends on finding the Pimpernel's identity. Still, she keeps her composure and asks that, should she deliver, she will get the damning letter about Armand,

"If I promise to help you in this matter, Chauvelin," she said pleasantly, "will you give me that letter of St. Just's?"