Baron Trigault's Vengeance by Emile Gaboriau

Unusual strength of character, unbounded confidence in one's own energy, with thorough contempt of danger, and an invincible determination to triumph or perish, are all required of the person who, like Mademoiselle Marguerite, intrusts herself to the care of strangers -- worse yet, to the care of actual enemies. It is no small matter to place yourself in the power of smooth-tongued hypocrites and impostors, who are anxious for your ruin, and whom you know to be capable of anything. And the task is a mighty one -- to brave unknown dangers, perilous seductions, perfidious counsels, and perhaps even violence, at the same time retaining a calm eye and smiling lips. Yet such was the heroism that Marguerite, although scarcely twenty, displayed when she left the Hotel de Chalusse to accept the hospitality of the Fondege family. And, to crown all, she took Madame Leon with her -- Madame Leon, whom she knew to be the Marquis de Valorsay's spy.

But, brave as she was, when the moment of departure came her heart almost failed her. There was despair in the parting glance she cast upon the princely mansion and the familiar faces of the servants. And there was no one to encourage or sustain her. Ah, yes! standing at a window on the second floor, with his forehead pressed close against the pane of glass, she saw the only friend she had in the world -- the old magistrate who had defended, encouraged, and sustained her -- the man who had promised her his assistance and advice, and prophesied ultimate success.