An engineer and a professor attempt to build and test an underwater habitat for human beings. However, the environment they are doing this in may not be as stable as expected.
Carl Denham escapes trouble in New York by getting on a ship bound for a distant land. He gets into a fight and is made to disembark on Skull Island where he alights on a smaller version of King Kong.
A rescue team is sent to Mars to bring back an astronaut who claims that a Martian monster killed his team. As they return to Earth, they sense the presence of the creature in the spaceship.
A professor and his colleagues follow an explorer's trail down an extinct Icelandic volcano to the Earth's centre. However, they face many challenges in their quest.