In You’ll Be the Death of Me, McManus embraces the classic mystery novel structure in which solving the mystery of Boney’s death becomes the engine that drives the plot forward. All three protagonists rely on instinct as an important tool to supplement the scarce clues available. The novel explores the rewards that come when an instinct pays off as well as the serious risks involved in acting without evidence. McManus builds dramatic tension as the protagonists’ instincts lead them to conclusions that are alternately correct, leading them to the next clue, or dramatically incorrect, placing them in danger.

Mateo’s instinctual distrust of his cousin Autumn’s boyfriend, Gabe, ultimately proves key to unraveling the entire mystery. Although Autumn complains about Mateo’s “irrational dislike” (14) of Gabe, Mateo maintains his stance on “Loser Gabe,” a nickname he uses multiple times throughout the novel (80, 123, 163, 204). Mateo’s distrust of Gabe gives his mission to understand what Autumn is caught up in a clear direction. Even when it’s clouded by Ivy and Cal’s obsession with Lara Jamison and Dominick Payne, Mateo visualizes his instinct as a thread running through the mystery: “not a common thread, exactly, but a loose one.