On a radio program, adventurer Drew Allen tells his his audience about his various travails: Despite his poor luck in recovering lost treasure, he is offered a job by Cyrus P. Adams, who seeks to uncover millions of dollars worth of pearls from the South Sea island of Kashira, upon which he was once shipwrecked. Although he is warned that three previous expeditions have failed to return, Drew takes the challenge and leaves the next day in Adams' seaplane. Along for the trip are stowaways Pete McGillicutty and Tony Romans, and the three are soon forced to make an emergency landing during a thunderstorm. They are taken by the natives of Kashira to the throne of white princess Sharon, who warns them that they will be killed if they attempt to steal the island's treasures. For their own protection, Drew, Pete and Tony are imprisoned by the island's ruling Council of Three, but are saved from a fiery death at the hands of a native mob by Captain William Beemis, the only other outsider on the island. Beemis, Adams' long-lost partner, reiterates Sharon's warning and tells the men that after he found Sharon as a shipwrecked child, the natives came to believe that she had been delivered to the island by the Sun God. Drew, Tony and Pete are later released from jail in order to attend the "Song of the Sarong" ceremony, in which Sharon is expected to declare her love for her betrothed, Kalo. Instead, Sharon mysteriously selects Drew as her mate, causing the jealous Kalo to plot the American's demise. While Tony and Pete begin to feel guilty about their plans to steal the island's pearls, the promise of fortune still clouds Drew's eyes. Beemis tries to explain to Drew that the pearls are a part of the island's religious customs, but Drew tells the captain that he rejected his faith after seeing children killed in the bombing of a church during World War II. Later, Drew convinces Sharon to take him to "The Temple of Tears," the pearl shrine, but she is stopped by Mahu, her guardian, before she can give Drew the key to the sacred temple. Despite his growing affection for Sharon, Drew makes a deal with Kalo, who shows him a secret passageway into the temple in return for a share of the treasure, along with passage to America. The deceitful Kalo, however, blows up their seaplane before they can escape the island. Realizing that he has been given a second chance with Sharon, Drew attempts to return the stolen pearls, only to be captured by the native guards. Drew, Tony and Pete are sentenced to death by fire, but through Sharon's prayers, a rainstorm breaks out, extinguishing the flames and saving the three men. Learning that her mother was a missionary, Sharon converts the island to Christianity, and inspires a reawakening of faith in Drew.