[1] The novel responds to Ann Radcliffe's famous Gothic novel A Sicilian Romance (1790), especially through its plot of a disenfranchised young woman seeking her lost mother.

She gives birth to an illegitimate daughter, also named Rosalie, whom she secretly gives to her Protestant friend Mrs. Lessington to raise.

Rosalie Lessington repeats her mother's misfortunes through an illicit affair with Harry Montalbert, who is unbeknownst to her a distant relation.

They elope, but Montalbert refuses to tell his family, leaving Rosalie (the younger) alone with an infant in Messina while he visits his mother.

When Montalbert returns to Messina, rather than seeking them he pursues revenge on a man whom he falsely suspects of conducting an affair with Rosalie.