Watch Mystery in the Bermuda Triangle (1979) : Full Movie Online Free Beautiful Silvia and Sandra disappear mysteriously at the Bermuda Triangle. Santo, Blue Demon and Mil Mascaras, a team of super-heroes, go into action to try to find them. Soon they find out that evil Scientist Dr. Gro has developed a device to make people and objects to disappear blaming the famous vanishings of ships, airplanes and human beings on Mother Nature. Cast: Santo el Enmascarado de Plata, Blue Demon, Mil Mascaras, Silvia Manrquez and, Sandra Duarte