Lady Carbury is beset by worries about her career and the futures of her son and daughter. She tries to flatter editors into reviewing her new book favorably; she tries to persuade her daughter Hetta to marry her cousin Roger Carbury; and she hopes to find an heir to marry her wastrel son, Sir Felix.

Roger Carbury is deeply in love with Hetta, but Hetta loves Roger’s friend, Paul Montague. Roger earlier persuaded Paul to break with his American fiancé, Mrs. Hurtle, arguing that her vagueness about her past, coupled with rumors that she fought a duel with her husband and shot a man, make her an unsuitable wife for an English gentleman. When Paul falls in love with Hetta, however, Roger feels betrayed.

Sir Felix is a financial drain on his mother; his chief pastime is gambling with other dissolute young gentlemen at their club, the Beargarden. He reluctantly agrees to his mother’s plan that he court Marie Melmotte, the only child of the arrogant financier Augustus Melmotte. Melmotte is in London only for a short time and is dogged by rumors of past shady dealings, but he establishes himself as London’s leading financial genius. Felix’s wooing of Marie lacks spirit, but Marie thinks him beautiful and determines to marry him despite her father’s opposition and preference for another suitor, Lord Nidderdale, whose family connections are superior to those of Sir Felix. Marie, who knows she has control over money that her father settled on her in order to make it secure if his speculations fail, devises a plan whereby she and Sir Felix will elope to New York. Melmotte’s men seize Marie in Liverpool before her ship sails, however, and Sir Felix does not leave London at all, instead spending the night gambling away the money provided him by Marie and his mother. Lady Carbury, in anguish over her son’s behavior, turns for help to Mr. Broune, an editor with whom she flirted and whose marriage proposal she rejected, but with whom she begins to develop a more honest intimacy.

Melmotte skillfully draws members of the British upper classes into his financial schemes, the biggest of which involves selling shares in a projected railroad from Utah to Mexico. Montague is made a partner in the scheme through his association in California with Hamilton Fisker, a wheeler-dealer who originates the railroad plan. Melmotte organizes a toothless board of directors, including English aristocrats with no financial expertise, among them Sir Felix Carbury and Adolphus Longstaffe. Longstaffe is a Suffolk squire; unlike Roger, Longstaffe has social ambitions that lead him to live far beyond his means.

Longstaffe’s financial straits lead him to sell one of his properties, Pickering, to Melmotte (and foolishly to give Melmotte the title deeds before Melmotte pays him) and to suggest that his daughter Georgiana stay with the Melmottes in London. Georgiana despises the Melmottes but thinks her only hope of finding a husband is to spend the social season in London. When Georgiana becomes engaged to the banker Mr. Brehgert, her family is outraged that she would marry a Jew. Her father orders her to return to Caversham, and she writes Brehgert such an insensitive letter that he breaks off the engagement.

Melmotte’s aura of astounding wealth and his businsses’ ever-increasing profits move political leaders to sponsor his candidacy for Parliament. The climax of the political campaign coincides with a magnificent dinner Melmotte gives for the visiting emperor of China. Melmotte is elected, but many of the social and political elite of London who vied for tickets to the dinner fail to attend when rumors arise...