"The Amethyst Cross" by Fergus Hume is a novel written in the early 20th century. Set against a backdrop of romance and mystery, the book revolves around the complex relationships and conflicts experienced by its main characters, particularly Lesbia Hale and her love interest, George Walker. Their engagement faces challenges from Lesbia's stern father, Walter Hale, whose mysterious connections and desires complicate their romance, as well as the significance of a peculiar amethyst cross that appears to hold deeper secrets. At the start of the novel, readers are introduced to Lesbia and George as they share a romantic moment by the Thames. However, their idyllic scene is disrupted by Walter Hale's unexpected arrival, revealing his disapproval of their engagement and a strange obsession with a cross that Lesbia has inherited from her late mother. Following this confrontation, the plot thickens with George being assaulted under mysterious circumstances, and an exploration of the theft of the cross from his home leads to further intrigue. Lesbia's inner turmoil about her father's behavior and George's predicament sets the stage for a convoluted tale of love, familial obligations, and hidden truths. (This is an automatically generated summary.)