Initially, the mood of Flatland instills a sense of intense curiosity in its readers. Abbott's strange and methodological descriptions of a peculiar two-dimensional world are intriguing and disorienting, inviting readers to immerse themselves in a reality vastly different from their own. This curiosity is then further fueled by detailed descriptions of Flatland's geometry and its related societal structures. The more A Square explains, the more questions Abbott’s reader is left with.
As the narrative progresses, the novel’s sharp satire begins to come to the fore. The reader feels amused at the jokes and at A Square’s dry wit while also feeling a growing sense of disgust at the harsh and violent rules of the two-dimensional world. Flatland's society, with its unyielding class system and absurd gender roles, mirrors the flaws and injustices present in Victorian society (which are, to an extent, probably still familiar to the reader). This parallel creates a confusing mood of mixed amusement and discomfort, as readers are asked to recognize the ridiculousness of many conventional social constructs, both in the fictional world and in reality.
A brief period of hope for change and a sense of wondering curiosity surfaces as The Sphere introduces A Square to the concept of a third dimension. This revelation opens up new possibilities and prompts both A Square and the reader to reflect on the limits of their own worldviews, as it suggests the potential for transcending narrow perspectives and embracing broader, more inclusive viewpoints. However, even the comparatively expansive views of A Sphere are limited, as he roundly dismisses A Square’s inquiries about the possibility of there being a fourth dimension.
Unfortunately, the novel ends on a note of misery and resignation. Abbott reveals that A Square has been narrating the entire story from prison, as he has been given a life sentence for spreading seditious ideas. A Square reflects on the limitations of his world and bemoans the unlikeliness of widespread change if people remain resistant to new ideas. The reader is left with a sense of melancholy and discontentment, pondering the difficulties of challenging entrenched beliefs.