The sudden, inexplicable death of the heir to Otranto on his wedding day triggers a frantic struggle for power and succession within a crumbling noble house. Manfred, the lord of the castle, attempts to secure his lineage by forcing a marriage upon his son's betrothed, Isabella, despite the moral and legal implications. His objective is met with resistance from both the young woman and a series of increasingly bizarre, supernatural occurrences that threaten the structural and spiritual integrity of the castle. The narrative unfolds through a third-person perspective that emphasizes the claustrophobic atmosphere of the setting and the mounting paranoia of the characters.

Readers and critics frequently identify this work as the foundational text of the Gothic genre, noting its influence on subsequent horror and romantic literature. Discussion often centers on the deliberate artifice of the prose and the rapid, almost theatrical pacing of the supernatural events. Many observers highlight the contrast between the novel's archaic, stylized language and the raw, visceral nature of the plot's central anxieties. Scholars often analyze how the text balances the internal psychological turmoil of its characters with the external, often absurd, manifestations of the uncanny. The work remains a primary point of reference for those interested in the evolution of suspense and the historical development of the macabre in English literature.