The sudden, inexplicable death of a young nobleman on his wedding day triggers a series of supernatural events that threaten the usurping ruler of Otranto. Manfred, the lord of the castle, attempts to secure his lineage through forced marriage and political maneuvering, only to be thwarted by spectral manifestations and the weight of an ancient prophecy. The narrative follows the frantic efforts of Manfred to maintain control while the rightful heir emerges from the shadows. Written in a dramatic, heightened prose style, the story utilizes a third-person perspective to track the rapid escalation of chaos within the castle walls.

Readers and critics frequently identify this work as the foundational text of the Gothic genre, noting its influence on subsequent horror literature. Discussion often centers on the deliberate use of melodrama and the stark contrast between the villainous Manfred and the virtuous characters who oppose him. While some modern readers find the prose style archaic or the pacing overly frantic, the book remains a subject of study for its role in establishing tropes like the haunted castle and the family curse. Scholars highlight how the text balances traditional romance elements with an atmosphere of dread that was unprecedented at the time of its publication.