Whilst Derues remained at Buisson-Souef, Monsieur de Lamotte received several letters from his wife, some from Paris, some from Versailles.  She remarked that her son and herself were perfectly well....  The writing was so well imitated that no one could doubt their genuineness.  However, Monsieur de Lamotte’s suspicions continually increased and he ended by making the cure share his fears.  He also refused to go with Derues to Paris, in spite of the latter’s entreaties.  Derues, alarmed at the coldness shown him, left Buisson-Souef, saying that he intended to take possession about the middle of spring.

Monsieur de Lamotte was, in spite of himself, still detained by ill-health.  But a new and inexplicable circumstance made him resolve to go to Paris and endeavour to clear up the mystery which appeared to surround his wife and son.  He received an unsigned letter in unknown handwriting, and in which Madame de Lamotte’s reputation was attacked with a kind of would-be reticence, which hinted that she was an unfaithful wife and that in this lay the cause of her long absence.  Her husband did not believe this anonymous denunciation, but the fate of the two beings dearest to him seemed shrouded in so much obscurity that he could delay no longer, and started for Paris.

His resolution not to accompany Derues had saved his life.  The latter could not carry out his culminating crime at Buisson-Souef; it was only in Paris that his victims would disappear without his being called to account.  Obliged to leave hold of his prey, he endeavoured to bewilder him in a labyrinth where all trace of truth might be lost.  Already, as he had arranged beforehand, he had called calumny to his help, and prepared the audacious lie which was to vindicate himself should an accusation fall upon his head.  He had hoped that Monsieur de Lamotte would fall defenceless into his hands; but now a careful examination of his position, showing the impossibility of avoiding an explanation had become inevitable, made him change all his plans, and compelled him to devise an infernal plot, so skilfully laid that it bid fair to defeat all human sagacity.

Monsieur de Lamotte arrived in Paris early in March.  Chance decided that he should lodge in the rue de la Mortellerie, in a house not far from the one where his wife’s body lay buried.  He went to see Derues, hoping to surprise him, and determined to make him speak, but found he was not at home.  Madame Derues, whether acting with the discretion of an accomplice or really ignorant of her husband’s proceedings, could not say where he was likely to be found.  She said that he told her nothing about his actions, and that Monsieur de Lamotte must have observed during their stay at Buisson (which was true) that she never questioned him, but obeyed his wishes in everything; and that he had now gone away without saying where he was going.  She acknowledged that Madame de Lamotte had lodged with them for six weeks,