“‘We have each been duped,’ answered Gaudin.

“‘She will play me no longer. As far as I am concerned,’ said Theria, ‘you are welcome to all her affections, and I shall reckon you as one of my best friends for your visit this evening.’”

The visit was destined to have an unexpected end, however, for the attention of the Guet Royal, or night-guard, had been called to the clashing of swords.

“Some young men, who had come up with the guard as they were returning from their orgies, pressed forward with curiosity to ascertain the cause of the tumult. But from one of them a fearful cry of surprise was heard as he recognised the persons before him. Sainte-Croix raised his eyes, and found himself face to face with Antoine, Marquis of Brinvilliers!”

The late combatants threw dust in the eyes of the lady’s husband cleverly enough by pretending that Sainte-Croix had rescued her from the unwelcome attentions of Theria, who had mistaken her in the uncertain light for a lady with whom he had an appointment. The cloak which the Marchioness wore, together with the darkness of the night, had prevented his discovering that she was not the person he expected until her cries had brought in Sainte-Croix, who was passing, as he said himself, “to his lodgings in the Rue des Bernardins.”

The lady went home with her husband, and Sainte-Croix retired to his lodgings, there to meditate on the perfidy of his mistress. The Chevalier de Sainte-Croix was even more learned in poisons, and less scrupulous in the use of them, than his mistress; and in his first gusts of passion, on discovering her treachery, he was inclined—in the hate of her that took temporary possession of him—to subject her to their effect; but reflection produced demoniacal results. She should be spared to kill those who ought to be near and dear to her!

“‘I will be her bane—her curse!’ he exclaimed. ‘I will be her bad angel!... And I will triumph over that besotted fool, her husband,’ etc.

“He opened a small, iron-clamped box, and brought from it a small packet, carefully sealed, and a phial of clear, colourless fluid.

“‘I have it! It is here—the source, not of life, but of death!’

“Almost as he speaks, he is summoned by the femme de chambre of the Marchioness to an interview at her residence at her father’s house, the Hôtel d’Aubray. The Chevalier found the enchantress in studied disarray. She might have been made up after one of Guido’s Magdalens,” says the author, “so beautiful were her rounded shoulders, so dishevelled her light hair,” etc.