In the evening the sisters, having grown somewhat calmer, decided that their best course would be to write to Mathieu. Norine remembered that he had called on her a few years previously to ask if Alexandre had not been to see her. He alone knew all the particulars of the business, and where to obtain information. And, indeed, as soon as the sisters' letter reached him Mathieu made haste to call on them in the Rue de la Fédération, for he was anxious with respect to the effect which any scandal might have at the works, where Beauchêne's position was becoming worse every day. After questioning Norine at length, he guessed that Alexandre must have learnt her address through La Couteau, though he could not say precisely how this had come about. At last, after a long month of discreet researches, conversations with Madame Menoux, Céleste, and La Couteau herself, he was able in some measure to explain things. The alert had certainly come from the inquiry intrusted to the nurse-agent at Rougemont, that visit which she had made to the hamlet of Saint-Pierre in quest of information respecting the lad who was supposed to be in apprenticeship with Montoir the wheelwright. She had talked too much, said too much, particularly to the other apprentice, that Richard, another foundling, and one of such bad instincts, too, that seven months later he had taken flight, like Alexandre, after purloining some money from his master. Then years elapsed, and all trace of them was lost. But later on, most assuredly they had met one another on the Paris pavement, in such wise that the big carroty lad had told the little dark fellow the whole story how his relatives had caused a search to be made for him, and perhaps, too, who his mother was, the whole interspersed with tittle-tattle and ridiculous inventions. Still this did not explain everything, and to understand how Alexandre had procured his mother's actual address, Mathieu had to presume that he had secured it from La Couteau, whom Céleste had acquainted with so many things. Indeed, he learnt at Broquette's nurse-agency that a short, thickset young man with pronounced jaw-bones had come there twice to speak to La Couteau. Nevertheless, many points remained unexplained; the whole affair had taken place amid the tragic, murky gloom of Parisian low life, whose mire it is not healthy to stir. Mathieu ended by resting content with a general notion of the business, for he himself felt frightened at the charges already hanging over those two young bandits, who lived so precariously, dragging their idleness and their vices over the pavement of the great city. And thus all his researches had resulted in but one consoling certainty, which was that even if Norine the mother was known, the father's name and position were certainly not suspected by anybody. When Mathieu saw Norine again on the subject he terrified her by the few particulars which he was obliged to give her.