Admiral Nelson is kidnapped by a group of German survivors of WW II who dream of establishing the Fourth Reich. They plan to use Nelson, along with a group of other kidnapped scientists, to bring this about.

When a mass missile launching by a foreign power sets the U.S. on nuclear alert, the Seaview goes into a fail-safe maneuver, but is the launch really what it appears to be, and does this actually mean it's "doomsday?"