In 1927 Detroit, Michigan, Dale Gordon, daughter of automobile maker R. J. Gordon, practices racing her father’s fastest and most sophisticated car yet, the Gordon Packard. R. J. has invested nearly his entire fortune in perfecting the vehicle. A potential backer is impressed, but reluctant to fund mass production until he sees the vehicle tested in the most grueling race in the world, the Sahara International Rally. During a drive to resolve a transmission malfunction, the car crashes, and R. J. is seriously injured. On his deathbed, he tells his daughter that his dream is to win the Sahara Rally and prove the Gordon Packard is the finest automobile in the world. After her father’s passing, Dale enters the race, but must disguise herself as a man to qualify. Arriving at the start in Morocco, Dale is accompanied by two crewmembers, mechanics “String” and Andy. She and the other competitors are briefed about the warfare between Chambra and Hamancha tribesmen along the desert course, and warned that the tempting, shorter route is more dangerous. Soon after the race begins, Dale removes her male disguise, shocking the other contenders. Taking String’s advice, she elects to take the short route, along with the zealous German team, led by Von Glessing. While on a break near a water well, the three Americans are captured by Chambra tribesmen and their leering warlord, Rasoul. Dale fights back when Rasoul tries to seduce her and sets fire to his tent. After she flees into the desert at night, the Chambra find her the next day, passed out in the sand, and return her to their camp. Meanwhile, Von Glessing, who also operates as an arms dealer, sells a machine gun to Lord Beg, the Hamancha tribal leader, who immediately uses the weapon to overpower a group of attacking Chambra. Back in his tent, Rasoul tries to seduce Dale again, but is interrupted by the Chambra ruler, Sheik Jaffar. The handsome, young Jaffar first noticed the beautiful American girl when she arrived in Morocco and declares his own “claim” to her. Rasoul is reluctant to relinquish ownership of Dale, whom the Chambra call “the blue-eyed demon,” but Jaffar announces he will marry the girl to prove his entitlement to her. Jaffar assures Dale that she and her two teammates are safe under his protection and takes her to a secret waterfall to bathe. Dale allows the charming Jaffar to kiss her, but also tells him why she must return to the race and feels confident he understands. However, back at the camp, Dale is shocked when Cambridge, Jaffar’s British manservant, informs her that she is expected to marry the sheik, which means she cannot leave. Dale remains defiant about her freedom and refuses to submit. When Lord Beg and the Hamancha tribe launch a surprise attack on the Chambra camp, Dale risks her life to plant explosives in the sand and is responsible for blowing up the Hamancha assault vehicle. The Chambra cheer and now appreciate the fact that the “demon” girl is on their side, while Lord Beg is dismayed that the American seems to offer protection to his enemy. Meanwhile, Von Glessing gets back into the race after repairing his vehicle that Lord Beg crashed. At the camp, Dale realizes she has fallen in love with Sheik Jaffar and spends the night with him, but sneaks away in the morning to rejoin the rally. When she drives off in her racecar, Cambridge emerges from the backseat where he was sleeping under a blanket, and is happy to accompany her. Suddenly, Lord Beg’s tribesmen surround the car and capture Dale, while disabling the elderly Cambridge. At their caves, the Hamanchas tear Dale’s clothing and lock her in a cage. Meanwhile, Sheik Jaffar learns of Dale’s capture after a gypsy boy finds Cambridge lying wounded next to the abandoned racecar. Jaffar sets out to save his American bride, and, after some reluctance, Rasoul joins his leader on the difficult mission. While the rival tribes fight each other outside the caves, Dale is left in a pit surrounded by cheetahs and panthers. Just as the wild animals are about to attack her, Jaffar arrives and frees her. Once outside the caves, Dale and Jaffar dodge bullets and falling boulders, and Rasoul sacrifices his life to help them reach safety. Before dying, Rasoul orders Jaffar to stay in the desert and not follow the American girl. Meanwhile, String and Andy have driven the racecar from the Chambra camp to the gunfight at the Hamancha caves. When Jaffar notices another rally competitor speed by, he tells Dale to resume the race. She runs to the driver’s seat of the Gordon Packard, and String and Andy plan to meet her at the finish line, so the car will be as lightweight as possible. When Von Glessing looks in his rear-view mirror, he is dismayed to see the determined American girl back in the race. At the junction between the short and long routes, the British and Swedish teams challenge Von Glessing and Dale for the lead, but are soon forced off the road. Back at the battle site, Jaffar avenges Rasoul’s death and triumphs over Lord Beg and the Hamancha tribe. Approaching the finish line, Von Glessing and Dale are side by side, but Dale races to victory when the German car blows a tire at the last minute. Dale holds the trophy aloft as String and Andy arrive to embrace her. String tells the young champion that she has also saved her father’s company from bankruptcy. Beyond the cheering crowd, Dale sees Jaffar’s stallion and lets the horse lead her back to the sheik.