A few days later her revenge was complete when, in the King's presence, she rallied her sister on her low spirits. "You find the time pass slowly when you are away from Paris," she said; "nor am I surprised, since you have left your lover there"; to which Marie answered with a haughty toss of the head, "That is possible, Madame."
One formidable rival thus removed from her path, Madame de Soissons was not long left to enjoy her triumph; for another was quick to take the place abandoned by the broken-hearted Marie—the beautiful and gentle La Vallière, who was the next to acquire an ascendancy over the King's susceptible heart. Once more the Comtesse, to her undisguised chagrin, found herself relegated to the background, to look impotently on while Louis made love to her successor, and to meditate new schemes of vengeance. It was in vain that Louis, by way of amende, found for her a lover in the Marquis de Vardes, the most handsome and dissolute of his courtiers, for whom she soon developed a veritable passion. Her vanity might be appeased, but her bitterness—the spretoe injuria formoe—remained; and she lost no time in plotting further mischief.
With the help of M. de Vardes and the Comte de Guiche, she sent an anonymous letter to the Queen, containing a full and intimate account of her husband's amour with La Vallière—the letter enclosed in an envelope addressed in the handwriting of the Queen of Spain. Fortunately for Maria Theresa's peace of mind the letter fell into the hands of Louis himself, who was naturally furious at such treachery and determined to make those responsible for it suffer—when he should discover them. As, however, the investigation of the matter was entrusted to de Vardes, it is needless to say that the culprits escaped detection.
Madame de Soissons' next attempt to bring about a rupture between the King and La Vallière, by bringing forward a rival in the person of the seductive Mlle de la Motte-Houdancourt, proved equally futile, when Louis discovered by accident that she was but a tool in Madame's designing hands; and for a time the Comtesse was sent in disgrace from the Court to nurse her jealousy and to devise more effectual plans of vengeance.
What form these took seems clear from an investigation held at the close of 1678 into a supposed plot to poison the King and the Dauphin—a plot of which La Voisin, one of the greatest criminals in history, was suspected of being the ringleader. During this inquiry La Voisin confessed that the Comtesse de Soissons had come to her house one day "and demanded the means of getting rid of Mile de la Vallière"; and, further, that the Comtesse had avowed her intention to destroy not only Louis' mistress, but the King himself.
Such a confession was well calculated to rouse a storm of indignation in France, where Madame de Soissons had made many powerful enemies. The Chambre unanimously demanded her arrest; but before it could be effected, Madame, stoutly declaring her innocence, had shaken the dust of Paris off her feet, and was on her way to Brussels.
During her flight to safety, we are told, "the principal inns in the towns and villages through which she passed refused to receive her"; and more than once she was compelled to sleep on straw and suffer the insults of the populace, which reviled her as sorceress and poisoner. "We are assured," Madame de Sevigné writes, "that the gates of Namur, Antwerp, and other towns have been closed against the Countess, the people crying out, 'We want no poisoner here'!" Even at Brussels, whenever she ventured into the streets she was assailed by a storm of insults; and on one occasion, when she entered a church, "a number of people rushed out, collected all the black cats they could find, tied their tails together, and brought them howling and spitting into the porch, crying out that they were devils who were following the Comtesse."
In the face of such chilling hospitality Madame de Soissons was not tempted to make a long stay in Brussels; and after a few months of restless wandering in Flanders and Germany, she drifted to Spain where she succeeded in ingratiating herself with the Queen. She found little welcome however from the King, who, as the French Ambassador to Madrid wrote, "was warned against her. He accused her of sorcery, and I learn that, some days ago, he conceived the idea that, had it not been for a spell she had cast over him, he would have had children.... The life of the Comtesse de Soissons consists in receiving at her house all persons who desire to come there, from four o'clock in the evening up to two or three hours after midnight. There is, sire, everything that can convey an air of familiarity and contempt for the house of a woman of quality."
That Carlos' suspicions were not without reason was proved when one day his Queen, after, it is said, drinking a glass of milk handed to her by the Comtesse, was taken suddenly ill and expired after three days of terrible suffering. That she died of poison, like her mother, the ill-fated sister of our second Charles, seems probable; but that the poison was administered by the Comtesse, whose friend and protectress she was and who had every reason to wish her well, is less to be believed, in spite of Saint-Simon's unequivocal accusation. Certainly the crime was not proved against her; for we find her still in Spain in the following spring, when Carlos, his patience exhausted, ordered her to leave the country.
After a short stay in Portugal and Germany, Madame de Soissons was back in Brussels, where she spent the brief remainder of her days—"all the French of distinction who visited the City" (to quote Saint-Simon) "being strictly forbidden to visit her." Here, on the 9th October, 1690, her beauty but a memory, bankrupt in reputation, friendless and poor, the curtain fell on the life so full of mis-used gifts and baffled ambitions.