Juan Cabrillo and the crew of the covert combat ship Oregon have barely escaped a mission on the Congo River when they intercept a mayday from a defenseless boat under fire off the African coast. Cabrillo takes action, saving the beautiful Sloane Macintyre - who's looking for a long-submerged ship that may hold a fortune in diamonds. But what surprises Cabrillo is her story about a crazy fisherman who claims to have been attacked on the open sea by giant metal snakes in the same area. What begins as a snake hunt leads Cabrillo onto the trail of a far more lethal quarry - a deranged militant and his followers who plan to unleash the devastating power of nature itself against all who oppose them