In chapter 5, Lennie accidentally kills Curley's wife after stroking her hair in the barn. Curley organizes a lynch mob to hunt down and kill Lennie after discovering his wife's body. George joins the search to find Lennie before the mob does. The chapter builds tension through dramatic descriptions of the puppy's death, Lennie's interaction with Curley's wife, and her death. It also provides more depth to Curley's wife's character through her dialogue about her lonely life.