The Plant Man
Twin scientists - one good, one evil - come aboard Seaview. The evil twin is out to create a radioactive "plant man."
More from Season 3
Episode 1
Monster from the Inferno
Seaview is investigating a thousand-mile wide communication blackout. The source of this is a large alien brain found under the sea. It is broght aboard and takes over visiting scientist, Dr. Lindsay. With his help, and after possessing Captain Crane, the alien vows to take over the Seaview and after that, the Earth.
Episode 2
Werewolf
Two scientists examining a radioactive volcano are attacked by a wolf. One dies, and the survivor is infected by a virus that causes him to change from man to werewolf and back again. Admiral Nelson is exposed to the virus and the crew must find a vaccine.
Episode 3
The Day the World Ended
As Admiral Nelson demonstrates a new tracking device for a visiting U.S. senator, it seems to show that Seaview is the only life left on earth.
Episode 4
Night of Terror
Captain Crane searches for a lost diving bell containing Admiral Nelson, Chief Sharkey, and Dr. Sprague.
Episode 5
The Terrible Toys
Seaview is investigating a UFO. Along the way, they pick up a shipwrecked old man -- almost always a bad omen when our gallant crew finds a castaway! The bedraggled fellow has a sack full of strange, frightening toys capable of murder, and of destroying the submarine. Turns out the alien ship needs to melt down Seaview's hull for fuel. Nelson and Crane do their best to foil the aliens' plans before it is too late.
Episode 6
Day of Evil
A UFO crashes and an alien assumes the form of Admiral Nelson.
