Marilyn Fryser, a land developer, takes a few clients to see an estate with the intention of duping them. However, her plan is interrupted by a colony of giant ants who feed on human blood.
In the 21st century, aliens invade the solar system. Using Mars as their base, they steal all of Earth's space stations then brainwash or kill the crews.
A warship that can navigate land, sea, and air becomes Japan's last defence against an ancient underwater civilisation bent on reclaiming the surface world.