As a work of detective fiction, Guess Again explores secrecy and deception. Because of its shifting narration, Donlea imagines the lives of several different criminals, including Francis, Harriett, and Lindsay, to highlight the gap between appearance and reality, exploring how this space can be exploited to manipulate and endanger others.

The novel’s narrative structure creates multiple opportunities for dramatic irony, which lays bare the deception and manipulation at play. As Ethan investigates both his father’s death and Callie’s disappearance, the reader is privy to information that Ethan is not. His lack of awareness of the true nature of his situation, juxtaposed with the reader’s knowledge, heightens the sense of danger and tension throughout the narrative. Although Lindsay appears to be helping Ethan with the case, the reader learns that she is the one who has been driving much of the novel’s action, hoping to frame Blake for Callie’s murder all along. At the same time, Francis’s character is developed as almost superhuman: He is able to manipulate Ethan, gain information he shouldn’t have, and provide insight into Callie’s disappearance—despite the fact that he has been in prison for three decades. Because Ethan doesn’t know how Francis is able to come by this information, Francis appears to him to have powers that don’t really represent reality. Ethan doesn’t know just how far Francis’s reach goes and how much he is able to control. Ultimately, Francis takes advantage of his apparently superhuman qualities, creating a multi-layered plan that drives Ethan toward the truth of his father’s guilt in the Lake Michigan murders.

The novel also explores this idea through Harriett. For much of the novel, Harriett’s true identity is kept secret. She is referred to as simply “she” throughout her point of view chapters, creating yet another layer of deception that even the reader does not have access to. In this way, Harriett serves as a vessel to complicate Francis’s character: She carries out his actions to instill fear and motivate Ethan throughout the investigation. Her decision to steal Eugenia’s identity is a physical embodiment of this theme, paralleling Lindsay’s choice to deceive Ethan through the therapy video of herself disguised as Blake. Ethan’s role as an investigator is to look behind the façade that is shown to him, while the reader is similarly prompted to question what the narrative presents as reality.

Ultimately, Donlea’s novel explores the effects of lies, deception, and hidden truths, continuing to develop the message that things are not always as they appear. Although Lindsay and Harriett are brought to justice, Francis’s escape and the impending danger for Ethan as he pursues him highlight the dangers of lies and deception. For Ethan and Maddie, the gaps between appearance and reality prove life-threatening, reminding them that things are not always what they appear.