The startled smile that appears at this is gone again in an instant -- but Mary's face stays brighter than it was, even after it disappears.

"I am not sure it would quite make you a fool to doubt me," she says, truthfully. "But -- but I am very glad you do not."

She takes a deep breath, and goes on, more steadily, "Preparation may go far. Facts may, as well. I have no objection to using the truth as a weapon to my advantage."