JustWatch
S01 Episode 1
Melt Down
Schubert threatens to cause worldwide flooding by using powerful microwaves to melt Earth's polar ice caps, unless the government turns Mark Harris over to him.
49 mins · Thu, 22 Sep 1977
S01 Episode 2
The Mudworm
When a multimillion-dollar underwater probe malfunctions and begins attacking any ship that travels near it, Mark must reason with its highly advanced brain and convince it to stop.
49 mins · Thu, 13 Oct 1977
S01 Episode 3
The Hawk of Mu
Mark, investigating a power outage, discovers a centuries-old hawk statue from the legendary civilization of Mu. The statue, when used properly, can remove the power from a large area. Schubert discovers the power of the hawk statue and Mark must prevent him from taking it.
48 mins · Tue, 18 Oct 1977
S01 Episode 4
Giant
The oceans are leaking through a fissure in the ocean floor. A con-man named Muldoon agrees to guide Mark through the fissure to investigate. However, Mark is unaware either that giants inhabit the other side of the fissure or that Muldoon has already stolen gold from one of them.
48 mins · Tue, 25 Oct 1977
S01 Episode 5
Man O' War
Schubert threatens to cause worldwide flooding by using powerful microwaves to melt the earth's polar ice caps, unless the government turns Mark Harris over to him.
48 mins · Tue, 1 Nov 1977
S01 Episode 6
Shoot-Out at Land's End
When a multimillion-dollar underwater probe malfunctions and begins attacking any ship that travels near it, Mark must reason with its highly advanced brain and convince it to stop
48 mins · Tue, 8 Nov 1977
S01 Episode 7
Crystal Water, Sudden Death
Mark, investigating a power outage, discovers a centuries-old hawk statue from the legendary civilization of Mu. The statue, when used properly, can remove the power from a large area. Schubert discovers the power of the hawk statue and Mark must prevent him from taking it.
48 mins · Tue, 22 Nov 1977
S01 Episode 8
The Naked Montague
The oceans are leaking through a fissure in the ocean floor. A conman named Muldoon agrees to guide Mark through the fissure to investigate. However, Mark is unaware that giants inhabit the other side of the fissure and Muldoon has already stolen gold from one of them.
48 mins · Tue, 6 Dec 1977
S01 Episode 9
C.W. Hyde
Using his genetic scientists, Schubert produces a giant jellyfish which he intends to release unless his extortion demands are met.
48 mins · Tue, 13 Dec 1977
S01 Episode 10
Scavenger Hunt
Mark is somehow linked with a man named Billy, existing in a wild west town, who appears to be his twin. Investigating, Mark arrives in the town and discovers Billy had the same webbing as Mark but has had it removed.
48 mins · Tue, 18 Apr 1978
S01 Episode 11
Imp
Schubert attempts to make a satellite weapon to knock out the Earth's communications. However, to power the weapon he needs the energy crystals protected by a forcefield under the ocean. The crystals actually power the forcefield that protects an underwater city.
48 mins · Tue, 25 Apr 1978
S01 Episode 12
The Siren
An underwater landslide transports Mark to Verona, Italy... in the days of Romeo and Juliet.
1 h 30 mins · Tue, 2 May 1978
S01 Episode 13
Deadly Carnival
C.W. develops a Jekyll-and-Hyde personality after swallowing a mysterious liquid.
1 h 30 mins · Tue, 6 Jun 1978
