Latitude Zero

Three men: Dr. Ken Tashiro, Dr. Jules Masson, and journalist Perry Lawton, are trapped in a bathysphere when a seismic event cripples their descent. They struggle to breathe as pressure and darkness close in around them. Rescue teams on the surface race to reach them before their air runs out.

They are rescued by the supersubmarine Alpha, commanded by Captain Craig McKenzie. They are astonished to learn McKenzie is over 200 years old and that the Alpha was launched in the early 19th century. He explains that Latitude Zero lies below and protects its inhabitants from aging and death.

McKenzie ferries them toward Latitude Zero to heal Masson’s injuries. The Alpha showcases advanced technology that helps them survive hostile conditions. The group begins to grasp that Latitude Zero is a hidden world beneath the ocean surface.

The Alpha is attacked by Black Shark, a rival submarine led by Kuroiga who works for Dr. Malic. McKenzie uses superior technology to dodge and counter the assault, buying time to reach Latitude Zero.

The crew arrives at Latitude Zero, a utopian city fifteen miles below sea level at the equator and the International Date Line. Its inhabitants do not age or die and they quietly aid humanity’s technological and cultural progress. McKenzie explains the city’s purpose and the secret of its longevity.

Dr. Malic envisions destroying Latitude Zero with superweapons and grotesque grafts. He kidnaps Okada, a physicist allied with McKenzie, and his daughter Tsuruko to force cooperation. In a cruel display, he grafts condor wings onto a lion and later transplants Kuroiga’s brain into the creature as punishment.

Okada’s emergency signal triggers a rescue plan organized by Latitude Zero authorities. Tashiro, Masson, Lawton, Dr. Anne Barton, and Kōbo volunteer to help, equipped with Bond-style devices and special baths that render them resistant to harm. The mission moves to Blood Rock to confront Malic.

The rescue team infiltrates Malic’s island base, fights through guards, and reaches the control center. They manage to free Okada and Tsuruko and begin their escape. The operation demonstrates courage and the effectiveness of Latitude Zero’s advanced preparation.

During the escape, Malic boards the Black Shark and fires an onboard laser at the rescuers. Kuroiga turns against Malic, attacking the laser and undermining his plan. The confrontation escalates as the base destabilizes, forcing a perilous exit.

The island’s cliffs collapse onto the Black Shark, destroying the base and killing everyone aboard. The heroes escape with Okada and Tsuruko, but Latitude Zero’s secret is endangered by the catastrophe.

Lawton is the only visitor eager to return to the surface world. He is picked up by a US Navy vessel, but discovers that his knowledge of Latitude Zero has vanished. The mystery leaves him to doubt whether the adventure ever happened.

Just as he contemplates resuming a normal life, the ship receives news that a cache of diamonds has been deposited in Lawton’s name in a New York safe deposit box. The ship is then instructed to change course toward Latitude Zero, hinting that his journey may not be over after all.