Scientists on a tropical island are measuring the radioactivity of a volcano when they are attacked by a wolf. Prof. Hollis shows signs of lycanthropy and threatens everyone on board, especially Admiral Nelson, whom he has infected.
After the arrival of a newly elected U.S. Senator to inspect Admiral Nelson's new weapon, strange things begin to happen, culminating with the realization that everyone outside of the Seaview appears to have disappeared from the Earth.
An old man, adrift at sea, is rescued along with a sack of toys by the Seaview. The toys take on a life of their own and begin to sabotage the ship. The toys appear to be connected to an alien space ship lying on the ocean floor.
An emergency mission leads the Seaview to rescue Kowalski's brother Stan. Once on board, Stan's refusal to help anyone else threatens the sub's survival after it sinks to the ocean floor, a thousand feet below it's crush limit.
A controversial filmmaker's crew is killed by a creature on a remote island. The Seaview goes to investigate the incident. One of the crewmen has a special interest in the mission as his father was one of the victims.
Admiral Nelson wanders the Seaview and finds it abandoned except for Captain Crain and Chief Sharkey. He has no memory of what happened before or what the strange sounds over the intercom mean. Capt. Crane is also trying to kill him.
A scientist in an underwater sea lab has created a new form of plant life. His twin brother, who can control him telepathically, is on his way there via the Seaview, with plans of using the new plant creatures for his own sinister purposes.
While on a routine scientific expedition Capt Crane encounters a strange hybrid seaweed humanoid creature. Crane is captured by the creature and the crew of Seaview launch a desperate attempt to rescue Crane before his air runs out.
The Seaview encounters a strange structure on the sea floor. Investigating they discover a German submarine from WW2. Surviving Germans on-board think the war is still being fought. And they have weapons on-board of unimaginable destructive power.
While on routine patrol the Seaview begins to hear strange noises coming from an undersea canyon. Investigating they discover the source of the noise and the power behind the destruction of a British fleet in the area 200 years before.
The Seaview is tasked with transporting a Mummy from New York for special secret testing. It becomes apparent very quickly not all is as it should seem, and soon a terrible threat is unleashed on the crew of Seaview.
The Seaview is tasked with attempting a space probe launch from sea. To avoid interference a skeleton crew is manning the ship. While en route the ship encounters a strange object that unleashes a threat that could destroy Seaview and all on board
The Seaview is tasked with moving a series of crates supposed to contain statues dating from the time of Atlantis. Something far more sinister is in the crates and Capt Crane is the only one in a position to save the ship.
Crane and the Admiral are on a mission to secure a new element that could be used to control the world. While exploring an undersea cave events occur that leave the admiral as the only survivor of the expedition and a changed man.