A young aristocrat and an ambitious astronomer initiate a clandestine marriage that defies the rigid social hierarchies of nineteenth-century England. Lady Viviette Constantine, trapped in a lonely marriage, finds intellectual and romantic solace in Swithin St. Cleeve, a man of lower social standing and significant scientific promise. Their union faces intense scrutiny from the local community and the constraints of Victorian class expectations, which threaten to dismantle their future. The narrative follows their attempts to reconcile personal desire with the unforgiving social and economic realities of their time.

Readers frequently highlight the unconventional nature of the romance, noting how Hardy uses the astronomical setting to emphasize the insignificance of human social struggles. Discussion often centers on the tension between the protagonist's intellectual pursuits and the restrictive societal expectations placed upon them by their peers. Critics often point to the novel's focus on the fragility of reputation and the harsh consequences of defying class boundaries in the Victorian era. The pacing is often described as deliberate, allowing for deep reflection on the characters' motivations and the broader philosophical questions posed by the author. Many readers find the scientific imagery to be a unique element that distinguishes this work from other Victorian romances.