In 1877, Tahitians under the rule of aging Queen Pomare chafe at their position as a French protectorate and quietly plan a new war with assistance from Britain. Police inspector Pierre Duvois discovers natives attempting to unload a shipment of illegal rifles and confiscates the firearms. That night at a saloon run by American Mike Macklin, Duvois informs the British representative, Shoreham, of the arms seizure. Duvois then meets Mike for their customary game of chess and warns him against involvement with the suspected native uprising. Later that night, however, Mike visits Pomare, who admits to having waited over twenty years for the arrival of the British and liberation. When Pomare shrewdly suggests that Mike take the risk to sail to San Francisco to collect another shipment of rifles from the British, he agrees. Duvois quickly learns of Mike's intended voyage and questions him, but Mike declares that he is only sailing to retrieve his fiancée. Suspicious, Duvois insists on accompanying Mike, declaring himself his "best man." In San Francisco, Mike endures Duvios' incessant meddling before learning that old friend Gay Knight is performing at a local dance hall. Mike catches Gay's performance with her partner, Wanda Spence, then proceeds backstage, where he proposes to Gay, offering her $2,000. Crestfallen, Gay declines, as she recently wed. Having overheard the proposition, however, Wanda offers to marry Mike, who hesitantly agrees and gives her the money for her trousseau. The next day when Gay comes by to pick Wanda up for the wedding, she discovers her friend packing hastily, intending to flee with Mike's money. Gay advises Mike, who confronts Wanda and threatens her with arrest for attempting to steal his money. Chagrined, Wanda reluctantly goes through with the wedding, while in the harbor British contacts load Mike's boat with boxed rifles. Mike and Gay arrange to get Duvois drunk, and when he passes out, Mike and Wanda set sail. Mike advises his first mate Angelo not to reveal their cargo to Wanda, but she stays in her cabin for most of the voyage. When she finally emerges, Mike promises to return her to San Francisco in two months if she will play along for Duvois. Wanda remains indignant, but curiously observes the boxes being unloaded on the volcanic island of Kiloha, a few miles from Tahiti. Mike and Wanda then arrive in Tahiti to find Duvois there ahead of them. Sensing Wanda's unease, Duvois attempts to gain information from her about her journey, but she refuses to give details. Later, Wanda asks Mike to confide in her, but he remains evasive. Wanda's curiosity is piqued again when Mike's former girl friend and saloon dancer Mawaii arrives with a message from Shoreham that a small British fleet is expected that very evening. Mike secretly makes plans to bring the rifles from Kiloha, then dines with Wanda and Duvois. When Mike is called away, Duvois explains the island conflict to Wanda and warns her that Mike may be in danger if he involves himself, but Wanda again denies any knowledge of her husband's activities. Wanda waits up for Mike that evening and again pleads for him to confide in her, admitting that his behavior has motivated her to want to help. Surprised and pleased, Mike still refuses to divulge details of his trip to Kiloha. Wanda is later awakened by the arrival of Shoreham, who has come to inform Mike that the British have turned back and that Mike is walking into a trap if he delivers the rifles to Tahiti. Realizing that Duvois is their only hope, Wanda and Shoreham go to see him, then plead with Pomare to halt the native uprising. As Mike and his men reach the rifles on Kiloha, the volcano erupts, sending ash, lava and strong winds down upon them and over to neighboring Tahiti. Wanda protects Pomare from the blistering winds, while on Kiloha, Mike and his men struggle to evade the fire and lava. With the rifles destroyed and the fierce volcanic blast subduing the Tahitians, Pomare admits that she and her people must accept their tie to France, and calls off the rebellion. Reunited, Mike and Wanda realize their feelings for each other and decide to enjoy their marriage.