Sainte-Croix had addressed the little box, with its contents, to Madame de Brinvilliers in these terms: 'I humbly beg those into whose hands this box falls to do me the favour to return it into the hands of the Marquise de Brinvilliers, who lives in Rue Neuve-Saint-Paul, since all that it contains concerns her and belongs to her alone, and moreover it is of no use to anybody in the world but herself; and in case she dies before I do, to burn it, and all that is in it, without opening it or meddling with it; and so that no one may pretend ignorance, I swear by the God I adore, and all that is most holy, that I state nothing but the truth. If perchance any one contravenes my intentions, just and reasonable as they are, I charge it in this world and the next upon his conscience, for discharge of my own, and declare that this is my last will. Made at Paris, afternoon, May 25, 1670. _Signed_: Sainte-Croix.' Below were these words: 'There is a single packet addressed to Monsieur Pennautier, which is to be given to him.' The very energy of these formulæ impressed Commissary Picard. He sealed up the case and confided it to the care of two sergeants, Cluet and Creuillebois, so that the inventory might be made by the civil lieutenant in person. Sergeant Creuillebois took the box home.
It was Sainte-Croix' widow who on August 8--that is, the day when the box was discovered--sent word to Madame de Brinvilliers at Picpus that things belonging to her were under seal. The marchioness instantly sent some one to find the box. As that was no longer in Sainte-Croix' house, a servant was sent off to Commissary Picard to tell him that Madame de Brinvilliers desired to speak to him without delay. Picard answered that he was busy. The marchioness, however, herself hurried to Madame de Sainte-Croix, insisting on the box being given to her. It was nine o'clock at night. 'She complained of its having been sealed up, offered money to obtain it, proposed to break the seals in order to take out what was inside, and to substitute something else.' But the box had been taken away. 'It's very amusing,' she said, 'for Commissary Picard to carry off a box that belongs to me!' She got some one to take her to Sergeant Cluet, whom she made come down, so that she might speak to him from her carriage. 'The lady told him that Pennautier had come to her, and told her that he was anxious about the box, and would give fifty golden louis to have what was in it. She also said that all that was in the said box concerned Pennautier and herself, and that they had done everything in concert.' We see here the first step in a manoeuvre which Madame de Brinvilliers afterwards developed. Knowing that several of the papers in the box concerned Pennautier, she sought to link her cause with the financier's, speculating on his high position and influence.