Now that d’Artagnan’s managed to secure two of his friends, he goes off in search of the third. On his way to Athos, d’Artagnan thinks about how mysterious Athos is compared to the other musketeers. He wonders about what happened in Athos’s past to make him the way he is. There is a certain sadness to Athos that d’Artagnan cannot pin down.
The pattern of threes continues as d’Artagnan makes his way to Athos. Although the novel keeps its comic tone in this chapter, some darkness creeps in. Unlike Porthos and Aramis, Athos isn’t merely in a temporary crisis; whatever secret is eating away at him has been doing so for a long time.
D’Artagnan reaches the inn where he expects to locate Athos and finds it in utter chaos. Evidently, Athos and Grimaud have locked themselves in the basement of the inn and refused to come out. Instead, they are eating all of the food and drinking all of the wine in the basement. If anyone tries to enter the basement, Athos fires his weapon at them. Of course, the innkeeper is very upset by all of this, but D’Artagnan doesn’t feel that bad for him. After all, this is the innkeeper that betrayed the musketeers and yelled for them to be arrested. The innkeeper explains that he was only acting on the cardinal’s orders.
D'Artagnan enters the third and final inn to find that Athos and Grimaud have gotten revenge on the innkeeper who betrayed them. Although d’Artagnan doesn’t feel bad for the innkeeper, he is deserving of some sympathy. After all, he was simply acting on the cardinal’s orders and did not think he was doing anything wrong. Now, in consequence, his business is being destroyed.
During d’Artagnan’s conversation with the innkeeper, two Englishmen arrive and learn about the situation in the basement. Annoyed, they plan to go down and get Athos out themselves. Realizing how poorly that is likely to go, d’Artagnan steps in and promises to retrieve Athos from the basement himself. D’Artagnan is ultimately successful, though Athos and Grimaud are still incredibly drunk. As payment, d'Artagnan gives the innkeeper Athos’s horse since d’Artagnan has a better one for him anyway.
D'Artagnan knows that Athos will easily kill the Englishmen if he doesn’t step in and do something. Luckily, despite Athos’s drunken state, he recognizes d’Artagnan and comes out of the basement before he can do any further damage.
In his drunken state, Athos tells d’Artagnan a story, which he claims happened to a friend of his. It is clear to d’Artagnan that Athos’s “friend” is actually Athos himself. This “friend” once fell in love with a beautiful girl and decided to marry her. He didn’t know the girl’s background and married her purely out of love rather than anything to do with her social status. However, one day, after the two were married, the woman fell from her horse and Athos’s “friend” saw that the woman was branded with a fleur-de-lis, the mark of a criminal. Apparently, she received the mark for stealing sacred items from a church. Enraged, Athos’s “friend” murdered his wife by hanging her from a tree. This story shocks d’Artagnan, who pretends to pass out from drinking too much.
Finally, d’Artagnan learns more about Athos’s background and it is shocking. Although Athos’s wife is not entirely innocent, Athos’s response is barbaric. The novel’s original readership may have been more sympathetic to Athos than the modern reader, but even from a contemporary perspective, his actions are excessive. This is a major shift in Athos’s character. Previously, although flawed, the musketeers were all likeable and generally moral people. However, Athos’s past adds layers of grey into the mix and the line between hero and villain becomes blurred.