The narrator tells the reader that when Balzac's name is translated to Chinese, it's composed of four syllables and the name sounds exotically beautiful. The book is titled Ursule Mirouët, and Luo begins reading it that night. He finishes it at daybreak and passes it to the narrator, who sits in bed all day and finishes the book at dusk. The narrator explains that until this point, he'd heard nothing but "revolutionary blather" about Communism—this was his first experience reading about passion, love, and impulsive action. Further, even though the narrator knows nothing about France, he finds that the book is so relatable that it could've been written about his neighbors.
The narrator never suggests that there was any coin toss or "fair" way of deciding who got to read the book first. Luo gets it, which shows that his needs and desires come before those of the narrator and reinforces the narrator's sidekick status. The discussion of Balzac's name in translation hearkens back to the narrator's comment about Tibetan incense and the beauty of language in general. The idea that the novel is so highly relatable even to the narrator continues to develop the idea that art and literature are universal.
When the narrator finishes the novel, Luo, who had left that morning, still hasn't returned. The narrator says that Luo has certainly gone to see the Little Seamstress and relate Balzac's tale to her. Thinking of this, the narrator suddenly feels jealous for the first time. He tries to play his violin, but it sounds shrill.
Luo's relationship with the Little Seamstress is already causing him to act independently from the narrator, which indicates his growing maturity. The narrator, on the other hand, isn't enjoying his forced independence—he's not ready to make that leap yet.
The narrator decides to copy his favorite passages from Ursule Mirouët. He looks for paper but decides to write it on the inside of his sheepskin coat. Painstakingly, he covers the entire inside of his coat with tiny script and dozes off late at night.
By writing on his coat, the narrator turns his coat into an almost sacred object. Though the particulars are different, this follows the same line of reasoning that gives the tailor his high status on the mountain. Clothing is important, particularly when paired with literature.
At 3am, Luo wakes the narrator. Luo says he has something to show and pulls out a white handkerchief. He unfolds it slowly and the narrator realizes it's actually fabric torn from the Little Seamstress's shirt. Inside are beautiful leaves stained with blood. Luo explains that they're ginkgo leaves from a clearing near the Little Seamstress's village. He and the Little Seamstress had sex under the tree, and the blood on the leaves is hers. The narrator can barely think. Luo says the Little Seamstress laughed after they had sex.
Having sex certainly had nothing to do with the narrator in Luo's mind. However, for the narrator, it's an earthshattering discovery that makes it so he can't ignore Luo's growing maturity and independence. By sharing the leaves and story with the narrator, Luo reinforces the narrator's position as a sidekick and bystander to his romance.