The narrator, a wealthy retired lawyer living in quiet isolation on his estate, is interrupted by two runaway boys pretending to be pirates like Jean Lafitte and Henry L'Olonnois. Struck by a sudden longing for the romance and imagination of youth he never had, the man joins their band as a scrivener and purser. The unlikely crew embarks on a journey downriver in a makeshift pirate skiff, encountering various adventures, including a confrontation with a local pearl fisher.
As the voyage progresses down the Mississippi River toward the Gulf, the narrator's motivations shift. He discovers that the aunt of one of the boys is Helena Emory, the woman he once loved and lost. Prompted by jealousy and lingering devotion, he learns that Helena is traveling on a luxury yacht chartered by his former friend, Calvin Davidson, whom rumors suggest she is going to marry.
Driven by a sudden, reckless impulse, the narrator tracks down the yacht and, with his pirate companions, executes a daring boarding action to seize the vessel. He takes control of the ship, leaving Davidson behind, and steers the yacht southward into the bayous of Louisiana, holding Helena and her aunt as polite captives while he attempts to win back her heart.
Throughout the journey, the dynamic between the narrator and Helena remains a battle of wits and wills. She resists his high-handed tactics and questions his sanity, while he struggles between his old rational self and the role of a desperate buccaneer. Their conversations revisit the past, the reasons for their separation, and the values of ambition versus freedom.
As they elude pursuit by local authorities and Davidson's agents, the group navigates the shallow southern coastal waters. The narrative builds toward a quiet resolution where the boundaries between play and reality blur, leaving the narrator to confront the true motives behind his wild crusade for love and adventure.
