Michael O'Hara, an Irish sailor, encounters a mysterious and beautiful woman named Elsa Bannister in Central Park and saves her from a potential mugging. Grateful, Elsa offers Michael a job on her wealthy and disabled husband's yacht. Reluctant but intrigued by Elsa, Michael agrees. The yacht sets sail along the Mexican coast, where Michael becomes further entangled in the Bannisters' complicated and strained relationship. Elsa's husband, Arthur Bannister, is a brilliant but sinister criminal defense attorney, and their mutual friend George Grisby suggests a peculiar murder plot to Michael with a promise of substantial financial gain.

As the voyage progresses, tensions rise and loyalties are tested. Michael finds himself caught in a dangerous web of deceit, betrayal, and murder. The twisting narrative pulls him deeper into the Bannisters' manipulative game, leading to shocking revelations and perilous consequences. The story reaches a climactic point as it becomes clear that not everything is as it seems, and everyone has something to hide. From this moment onward, the plot hurtles toward an unpredictable and dramatic resolution.