A husband and wife Antarctic research team is killed by an experiment on plankton gone wild. Seaview arrives to investigate and take plankton samples. Soon the submarine is in danger of succumbing to the horrible, slimy growth. Nelson, Crane and crew face another problem: one of the three scientists on board the sub is an enemy agent.
Elenco: Richard Basehart , David Hedison , Robert Duvall , Terry Becker , Del Monroe , Paul Trinka , Richard Bull , Robert Dowdell .