The Three Musketeers
This story is D’Artagnan’s coming-of-age. When we first meet him, he’s riding a ridiculous yellow Béarnaise pony, has barely any money, and shoots dagger glances at anyone who looks at him cross-eyed. By the end of the novel, he’s a lieutenant in the service of His Majesty’s Musketeers. He’s made three best friends, saved the Queen’s honor, watched his true love die, and help execute a terrible criminal. Out of all the characters in the novel, D’Artagnan is the most central and the one whose personality evolves the most.