 In Brazil, Gloria s father is bankrupt, so he asks her to take the son of his potential financial savior on a day of boating planned with her boyfriend Danny and their best friend Jeff. Marcos is the rich kid, muscular but, because of a childhood illness, not a swimmer. Gloria is a materialist and a flirt, happy to tease Danny with Jeff and then to toy with Marcos while the others dive. Danny gets mad at Marcos, though, and tosses him into the water with a lifebuoy, then drives the boat to the far side of an island. When they return, Marcos is missing in the strong currents, presumed drowned, and the three have to figure out what to do. Alliances shift, plots hatch, and Davy Jones beckons.