Off the Malayan coast, four people escape from a pleasure cruise that is infested with bubonic plague, and are forced to plunge into the jungle with Montague, a guide.  Judy Jones, a prim Chicago schoolteacher, is more worried about sleeping close to her two male companions, Stewart Corder, a famous journalist and Arnold Ainger, an introverted chemist, than she is about the dangers of the jungle.  Her spirits are fortified by the gregarious socialite Mrs. Fifi Mardick, however.  As the men find Judy unattractive, they try to soothe her nerves by telling her they do not think of her as a woman.

After three exhausting days, Montague admits they are lost.  Judy worships Stewart as a hero after he saves her from a deadly cobra, and she attempts to ingratiate herself on him.  Her attempt fails miserably, however, when she accidentally burns his only shoes.  Unable to deal with his fury and both men's disregard of her, Judy strikes out on her own.  Her companions find her surrounded by the Semang tribe, who request payment of rice in exchange for safe passage through their territory.  The natives tie up the men and take Mrs. Mardick hostage, threatening to kill her if they do not return within one month with the rice.

After this experience, Judy takes command of the remaining group, ordering Montague to cut the men down.  Her self-confidence makes her more alluring, and Stewart and Arnold vie for her affection.  In time, Arnold and Judy fall in love, despite the fact that he has a wife back home.  He, too, has grown more confident, and feels more manly than he ever did in civilization.  The group discovers they have been walking in circles.

After returning to the camp, Stewart shoots what he thinks is a monkey, but is actually a Sakai pygmy.  When Montague tries to appease the pygmies by offering some of the rice shipment they hope to get when they find civilization, he is killed by an arrow through his throat.  Before he dies, he tells his friends that the Sakai will be forever disgraced because they have killed a white man, which is against their beliefs.  When another pygmy attacks Stewart, Arnold takes an arrow that was meant for Judy, and he collapses.  The natives tie Judy and Arnold to a tree while Stewart goes for water, and when he returns he releases them.

In the meantime, Mrs.  Mardick is ousted from the village because she has been teaching the women birth control.  The chief agrees that the birth rate will be up to women from henceforth, and Mrs.  Mardick is escorted to town.  Arnold recovers from his wound, and Stewart finally leads them out of the jungle.

When Arnold returns to his home, his wife cannot understand why he did not write her a letter, and believes herself to be the laughing-stock of her friends because of her neglectful husband.  Arnold wholeheartedly agrees to a divorce.  Stewart gains even more fame by relating his adventures over the radio, as does Mrs.  Mardick.  Judy returns to the classroom, but her class is interrupted one day by Arnold, who leads her out of the classroom, into his life.