An alien spaceship lands in the ocean, and Seaview is sent to investigate. Although Seaview is powerless in the vicinity of their ship, the aliens seem friendly, and Nelson manages to open negotiations. The military authorities, however, have other ideas, and Seaview may be in as much danger from human interference as from the aliens.
Elenco: Richard Basehart , David Hedison , Robert Duvall , Terry Becker , Del Monroe , Paul Trinka , Richard Bull , Robert Dowdell .