September 22, 1977 • 49m
Schubert threatens to cause worldwide flooding by using powerful microwaves to melt Earth's polar ice caps, unless the government ...Read more
October 13, 1977 • 49m
When a multimillion-dollar underwater probe malfunctions and begins attacking any ship that travels near it, Mark must reason with...Read more
October 18, 1977 • 48m
Mark, investigating a power outage, discovers a centuries-old hawk statue from the legendary civilization of Mu. The statue, when ...Read more
October 25, 1977 • 48m
The oceans are leaking through a fissure in the ocean floor. A con-man named Muldoon agrees to guide Mark through the fissure to i...Read more
November 1, 1977 • 48m
Using his genetic scientists, Schubert produces a giant jellyfish which he intends to release unless his extortion demands are met.
November 8, 1977 • 48m
Mark is somehow linked with a man named Billy, existing in a wild west town, who appears to be his twin. Investigating, Mark arriv...Read more
November 22, 1977 • 48m
Schubert attempts to make a satellite weapon to knock out Earth's communications. However, to power the weapon, he needs the energ...Read more
December 6, 1977 • 48m
An underwater landslide transports Mark to Verona, Italy...in the days of Romeo and Juliet.
December 13, 1977 • 48m
C. W. develops a Jekyll-and-Hyde personality after swallowing a mysterious liquid.
April 18, 1978 • 48m
Mark re-encounters Muldoon, his nemesis from "Giant," who is using a sea monster to make island natives sacrifice young girls to him.
April 25, 1978 • 48m
An impish little man enters an underwater station and causes the crew to become irrational simply by touching them. After three cr...Read more
May 2, 1978 • 1h 30m
While investigating the mysterious loss of three ships in one part of the ocean, Mark and the crew of the Cetacean encounter a sub...Read more
June 6, 1978 • 1h 30m
Mark goes undercover to investigate members of a carnival planning to break into a museum. The only way to break into the museum i...Read more