The Narrator gets sent home from work because he showed up with blood all over his pants. He leaves, thinking about how he’s given up his worldly possessions to live with Tyler and fight. When he’s home, he can hear Tyler and Marla having sex. Over time, Marla continues to come by to have sex with Tyler, though the Narrator never sees them in the same room together.
There’s a clear romantic triangle between the Narrator, Marla, and Tyler: The Narrator seems to resent that Tyler is having sex with Marla, even though he doesn’t say so.
To wash the Narrator’s bloody pants, Tyler teaches the Narrator how to make soap. From his fridge, he pulls out a big plastic bag full of fat, which he pours into a pot on his stove. As the fat slowly cooks on the stove (or “renders”), Tyler tells the Narrator that Marla is “trying to hit bottom.” The Narrator, Tyler claims, is nowhere near rock bottom—just because he’s given up his property doesn’t mean a thing. The Narrator’s sense of eerie calm is just “premature enlightenment.” Suddenly, Marla walks into the house, and the Narrator finds that Tyler is gone. Marla asks the Narrator what he’s cooking, and the Narrator doesn’t answer. She asks him to call her soon, and then leaves. As soon as she’s gone, Tyler comes back into the room—the Narrator is reminded of the way his parents used to behave around each other.
In this important passage, Tyler suggests that the Narrator is a long way from hitting “rock bottom.” The Narrator has allowed other people to hit him, and he seems to have embraced his own pain—yet Tyler insists that the Narrator is not yet enlightened (although Tyler doesn’t explain what he means by enlightenment). The Narrator doesn’t think it’s odd that Tyler and Marla are never in the room with him—he remembers his parents doing the same thing, and so isn’t suspicious of anything abnormal in their “love triangle.”
Tyler asks the Narrator not to mention him to Marla, ever. The Narrator promises not to do so. Tyler and the Narrator then return to making soap: they harden the rendered fat in the fridge. Tyler points out a layer of glycerin forming on the cooling fat—a product that can be used to make the explosive TNT.
Tyler’s request isn’t explained, and won’t make sense for a long time. Meanwhile, Tyler shows the Narrator that soap (a symbol of domesticity, civilization, and ordinary life) isn’t that far away from TNT (a symbol of chaos and destruction), as if civilization contains the seeds of its own destruction—an important idea in the book.
Suddenly, Tyler kisses the back of the Narrator’s hand. Lye (a caustic solution used in making soap), Tyler explains, hurts horribly and will give the Narrator a scar. He then pours lye on the Narrator’s hand.
Tyler insists that the Narrator is a long way from enlightenment—fight club was just the beginning. Here, he causes the Narrator tremendous pain, as if he’s trying to push the Narrator down toward “rock bottom.”