At an oasis in the Sahara Desert, Sheik Ahmed Ben Hassan presides over a marriage market, at which weathly tribesmen purchase brides, and ensures that his friend Yousaef is reunited with his sweetheart Zilah. Ahmed and his men then take some of the women to be sold in Biskra. Biskra, a large town where old traditions co-exist with the ways of foreign tourists, is the current home of the high-spirited Lady Diana Mayo. Despite the protests of her brother, Sir Aubrey, Diana is leaving the following morning on a tour of the Sahara, accompanied only by an Arab guide, Mustapha Ali, and his men. Diana is fascinated by the arrival of Ahmed and questions a gendarme, who tells her that the sheik will be hosting an entertainment at the casino, during which men will be able to gamble for the brides. Diana also learns that only Arabs are allowed entrance, and that the Paris-educated sheik is a rich tribal prince whose word is law in Biskra. Intrigued, Diana buys a dancing girl’s costume, then sits with the other women in the casino. When it is Diana’s turn to be displayed, she balks, and Ahmed deduces that she is not an Arab. After a bemused Ahmed escorts her out, Mustapha reveals that he is taking Diana into the desert, and Ahmed smiles. Soon after Diana begins her journey, Ahmed and his men ambush her. Upon being taken to Ahmed’s tent, Diana asks him why he has kidnapped her, and he replies, “Are you not woman enough to know?” After Diana rejects the sheik’s attempts to seduce her, he instructs his French valet, Gaston, and Zilah to attend her. Seeing Diana’s distress at her captivity, Ahmed keeps his distance, but insists that she wear traditional Arab garb instead of her western clothing. After a week of “sullen obedience,” Diana learns that Ahmed is to be visited by his friend, famed French novelist Dr. Raoul de St. Hubert. Diana is horrified that someone from “her” world will see her as a captive and assume that she has become Ahmed’s concubine. Seeing her concern, Ahmed orders Gaston to return Diana’s clothes to her, but when he kisses her, she still reacts coldly. Upset that his attentions repulse her, Ahmed leaves to meet Raoul. Later, while riding with Gaston, Diana broods on the upcoming encounter with Raoul, and runs away. In Biskra, Raoul reprimands Ahmed for abducting Diana, but the sheik protests that when an Arab wants a woman, he takes her. In the desert, Omair the bandit spots Diana alone and is about to seize her when Ahmed suddenly appears and saves her. Diana confesses that she ran away because of her shame over facing Raoul, and that night, Raoul discerns how uncomfortable Diana is. As the days pass, Raoul and Diana become friends, much to the dismay of Ahmed, who mistakenly assumes that Raoul is falling in love with her. One afternoon, as Raoul talks with Diana, news arrives that he is needed to tend to an injured man. Raoul notes Diana’s fear that Ahmed has been hurt, and her relief that is it someone else instead. Ahmed also sees her concern and is gratified. Meanwhile, in Omair’s stronghold, the bandit orders his spies to bring him news of Ahmed’s “white woman.” At the oasis, Ahmed returns Diana’s pistol to her when she promises not to run away, and she goes riding with Gaston. After Diana leaves, Raoul rebukes his friend for his treatment of her and begs him to return her to Biskra. Ahmed protests, then realizes that he has been in the wrong. Overcome with remorse, Ahmed tells Raoul to escort Diana to Biskra, then rides off alone. Meanwhile, Diana has been captured by Omair’s men, and Gaston has been wounded. When Ahmed rides through the desert, he finds the words, “Ahmed, I love you,” which Diana had scribbled into the sand before her capture. Ahmed is thrilled until he finds Gaston and learns what has occurred. Ahmed takes Gaston to Raoul, then assembles his men and rides for Omair’s fortress. As Omair is attempting to assault Diana, Ahmed and his men gain entry into the fort and battle their way to Omair’s inner sanctum, where Ahmed strangles his foe. Ahmed is wounded during the battle, and Diana anxiously accompanies him to the oasis. As Diana and Raoul watch over the unconscious Ahmed, Raoul reveals that Ahmed is the orphaned son of an English father and a Spanish mother. As a child, Ahmed was adopted by the former sheik, and was reared as an Arab. Diana then prays to God to take her instead of her beloved, and her tender words wake Ahmed. Overjoyed, the lovers embrace.