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"First Book Summary The Catalyst: The story begins with the heroine’s boyfriend leaving to join the Army/military. He is not a character in the book’s present timeline; he is effectively gone. The Letter: Before leaving, the boyfriend gives the heroine a letter (or she is given one after he departs). In this letter—or through a separate request—he tasks his best friend with the job of "looking after her" or "watching over her" while he is deployed. The Hero (The Best Friend): * He was roommates with the boyfriend (sharing an apartment or living together on a college campus). He comes from an impoverished, traumatic childhood background. He is a "player" and a "broken" character who struggles with his past. The Heroine: She is from a wealthy/well-off family, creating a clear social class gap between her and the hero. The Core Conflict: The book focuses on the tension and growing relationship between the "traumatized" best friend and the "left-behind" girlfriend. The hero is torn between his loyalty to the boyfriend and his feelings for the girl he was asked to protect."