Warlords of Atlantis

Professor Aitken, his son Charles, and Captain Daniels hire the Texas Rose to take them to sea in the early 20th century. They intend to use a diving bell designed by engineer Greg Collinson to search for proof of Atlantis. The voyage begins as they depart for the unknown waters.

Charles and Greg dive in the bell and are attacked by a reptilian sea monster that breaches the bell’s bottom. Greg impales the creature by thrusting a live wire into its mouth, electrocuting it. After the danger subsides, they discover a solid gold statue, a sign that Atlantis may lie beneath.

When the statue is hoisted aboard, mutineers Grogan, Fenn, and Jacko cut the diving bell line, trapping Greg and Charles at the sea floor. A shot strikes Professor Aitken in the back, shattering the group's resolve and triggering a mutiny for profit. The discovery turns from science into a life-or-death fight for survival.

An enormous octopus known as the Sentinel emerges from Atlantis and attacks the Texas Rose from the depths. The four crewmen, along with Greg and Charles in the bell, are captured and taken to a cavern beneath the ocean floor. Sandy, the ship's cabin boy, and Professor Aitken are left aboard, overwhelmed but alive.

In the cavern, Atmir greets the surface-dwellers and explains that Atlantis consists of seven cities. He describes two cities already sent down to the ocean and a third now deserted. The visitors begin to grasp the grand Atlantean plan for shaping Earth’s future.

Atmir escorts the humans through a prehistoric swamp inhabited by a millipede-like monster called Mogdaan, then they reach the Atlantean city of Vaar. Five of the men are thrown into a dungeon, while Charles is taken to Chinqua, the royal city. The stage is set for political intrigue as the Atlanteans reveal their power.

Charles is granted an audience with King Atraxon and Queen Atsil in Chinqua. They claim to be from Mars and reveal how their mind powers shape human history. They try to recruit Charles as part of their utopian project, testing his loyalties.

Greg and the surviving crew befriend Briggs, captain of the long-missing Mary Celeste, who becomes the unofficial leader of the human slaves. Briggs explains that Atlantis will grant them gills so they can never return to the surface, ensuring their loyalty. Delphine, Briggs’s daughter, joins Greg in planning an escape and resisting the Atlanteans' rule, including constant Zaarg attacks.

Briggs reveals a tunnel that leads toward Atraxon’s palace, offering a potential route to Charles’s rescue. The group steels themselves for a dangerous move while Zaarg attacks threaten Atlantis. The plan centers on slipping through Atlantean defenses to free Charles and escape to the surface.

Charles, seduced by the Atlanteans' utopian vision, initially resists leaving, but Greg knocks him out of the influence. Restored to reason, Charles decides to escape with Greg and the others. They break away from Chinqua and begin the journey back toward the ocean surface.

The group retraces their path through the swamp, and the Mogdaan monster returns, killing Jacko as they push on. They manage to reach the diving bell, though the journey is frantic and perilous. Delphine’s presence helps as she sacrifices safety to ensure the others’ escape.

Admir and the Guardians arrive at the diving bell and use telekinesis to unleash a violent surge of seawater to deter the escapees. The group presses on, while Delphine covers their retreat, knowing she can never return to surface life. They finally breach the water and make it back to the Texas Rose.

Back on Texas Rose, Sandy confronts the mutineers Fenn and Grogan and takes control of the situation with a pistol point. Daniels reveals that he shot the Professor, planning to profit from the discovery, throwing their dealings into chaos. Fenn and Grogan are restrained as they face the consequences of the mutiny.

The Sentinel attacks the Texas Rose and destroys the ship, ending the mutiny and altering the group’s fate. Daniels is crushed by a statue that appears in the chaos, while the remaining survivors escape in a lifeboat. The ending leaves a grim sense of uncertainty as the sea swallows the last evidence of Atlantis.