Constance relents and tells him all about the secret mission, and d'Artagnan promises to obtain a leave of absence and be on his way to London. Constance suddenly remembers the three hundred pistoles that the cardinal gave her husband, and she gives the money to d'Artagnan for the journey. D'Artagnan is delighted: "It will be twice as amusing to save the queen with His Eminence's [the cardinal's] money."
At that moment, they hear her husband returning with someone. D'Artagnan recognizes the person as "the man from Meung," and he is ready to attack him when Constance stops him because of his duty to the queen; in other words, first things first. They listen and overhear her husband's plan to supposedly relent and agree to go on the errand for his wife; then, after he has the queen's letter to Buckingham, he will take it to the cardinal.
On his way to Treville's house, d'Artagnan wonders if he should tell Treville about the secret mission; interestingly, Treville tells d'Artagnan to keep the details of the mission secret and, instead, to ask for whatever favors he needs. D'Artagnan says that the cardinal will do anything to keep him from getting to London, and Treville suggests that at least four people should go on the journey so that one of them might succeed in actually getting there. D'Artagnan says that Athos, Porthos, and Aramis will accompany him without demanding to know the nature of the secret mission. Accordingly, Treville writes out passes, and d'Artagnan goes to each of the musketeers and tells them to get ready for the trip. They discuss several tactics for successfully accomplishing the mission, but d'Artagnan tells them that they must all go together, not in separate directions, because if one of them is killed, the others can make certain that the letter is finally delivered to London. They agree and begin to make preparations to leave.
