A young aristocrat and a lower-class astronomer initiate a clandestine romance that defies the rigid social hierarchies of Victorian England. Lady Viviette Constantine, trapped in a lonely marriage, finds intellectual and romantic stimulation in Swithin St. Cleeve, a man significantly younger and of a lower social standing. Their objective to maintain this union is constantly threatened by the scrutiny of their peers, the constraints of class expectations, and the legal complications of their respective positions. The narrative, presented in a third-person perspective, utilizes the vastness of the cosmos as a recurring motif to highlight the insignificance of human social conventions.

Discussion often centers on the unconventional nature of the romance and how Hardy uses the cold, vast indifference of the stars to frame the petty social struggles of his characters. Readers frequently highlight the technical precision of the astronomical descriptions, which serve as a unique backdrop for a Victorian novel. Critics often note that the pacing reflects the slow, deliberate unfolding of the protagonists' social entrapment. The work is frequently analyzed for its bold challenge to the moral standards of its time, particularly regarding the portrayal of a woman seeking agency in her romantic life. Many readers find the juxtaposition of scientific inquiry and emotional vulnerability to be a defining characteristic of the narrative style.