Famous Last Words asks the reader to grapple, as Cam and Niall do, with elements that blur the lines between right and wrong. By suggesting that each person acts according to their own code, McAllister challenges the perception of right and wrong as moral absolutes. Luke’s actions during the siege dictate the way he’s perceived by others—his wife, the media, and the police—all of whom have specific contexts and biases that influence their understanding. For example, Tim exemplifies the perspective of law enforcement—he assesses the surveillance footage without bringing personal emotion or instinct to bear and lays out the ways Luke has violated the law. He delineates the argument Luke would need to make to prove self-defense, finds it insufficient given the evidence, and refuses to change his opinion without more definitive proof.

In contrast, Cam fixates on the idea of Luke being a “good” person as her primary evidence for Luke’s innocence. Even when all the evidence points to his guilt, Cam cannot bring herself to condemn him, creating an inner conflict: “Against her own moral code, Cam hopes that they’re searching for her husband, and that he got away, that he wasn’t shot” (89). Her intimate knowledge of who Luke is as a person in his everyday life motivates Cam to trust him despite the evidence against him. This inherent trust pushes her to act according to her instincts rather than the strictures of the law. She withholds information from the police to protect Luke even without knowing the circumstances that led to the hostage situation. She follows the clues he leaves without reporting him because her top priority is Luke’s well-being rather than seeing legal justice done. McAllister suggests that Cam acts in a way that’s right for her even if others—such as the police or the public—believe her actions are wrong, underscoring an intrinsic ambiguity. 

Similarly, Niall acts not on emotion but on instinct, emphasizing that his highest priority is to find the truth rather than simply close the case. His assessment of police protocol defines Niall’s own goals in opposition to the priorities of law enforcement: “This sort of game-playing has gone on [Niall’s] entire career. If this, then how will it look? If that, then how will we cover our own asses? The police are only ever interested in toeing the line” (219). When Niall initially arrives at the warehouse, all of his instincts tell him that Luke is not a killer, leading to an identity crisis for Niall when Luke shoots two men. Niall’s life changes because he believes he got the situation wrong, but his instincts continue to tell him he is right—an inner conflict that drives his actions throughout the novel. McAllister emphasizes his fixation on one tiny detail that signals to Niall his original assessment of Luke was right: “A small movement at the top of the screen, near the table, and then [Luke] walks forward purposefully, holding the gun out in front of him with straight arms. […] Niall pauses it, rewinds, but he can’t make out that small movement right at the start. He watches again” (27). His instincts and even his subconscious dreams push him to monitor Cam’s phone and scrutinize the surveillance footage even years after the crimes. 

The novel’s climax—in which Niall shoots George—validates Niall’s instincts and reaffirms the ambiguity of right and wrong. Having uncovered George’s guilt, Niall believes that George plans to attack Cam and Luke. He acts on instinct, making the split-second decision to shoot George, ultimately killing him. When he fails to find Luke and Cam in the lighthouse, Niall experiences a moral quandary—while his assumptions about George were incorrect, George’s orchestration of the hostage situation was, according to both Niall’s code and the law, wrong. Luke and Cam’s lie to shield Niall from legal repercussions endorses his view of right and wrong. Given George’s guilt, Cam and Luke determine that protecting Niall is the right thing to do. 

Although Niall, Cam, and Luke all commit morally questionable actions, McAllister provides each of them with a happy ending in which their lives and families are restored—absolving them of their wrongdoings throughout the novel and underscoring the idea of moral relativity. However, the novel’s final scene emphasizes the complexity of that happiness. The novel ends with Luke still struggling with what he did. The events have “hardened him into something perhaps more serious. Bleaker, sometimes, his humor darker. His view of his self fractured” (323). Although legally absolved of any wrongdoing, Luke still grapples with the morality of what he did, reinforcing the grey areas between right and wrong.