As a result of their incredible--but unintentional--discoveries in Mexico and Japan, the NWIDI team has become an unofficial resource for certain government agencies. A call from "the highest levels" sends them back to Mexico to investigate the nature and origin of sunken megalithic structures discovered just off the northwestern coast of Cuba. More than 2,100 feet below the surface, the site gives up secrets from the ancient past as well as the days of the Cold War but the team's exploration is cut short by a Cuban gunboat.