Two escaped convicts, Gary Tommy Cook and Lon Gary Clarke, are discovered hiding aboard a rocket by scientist Dirk Green Michael Whalen, who forces them to pilot the spaceship to the Moon because he is secretly a Moon man seeking to return home. Dirk’s ally Steve Dayton Richard Travis and Steve’s fiancée June Saxton Cathy Downs learn the vessel is about to launch and secretly board to investigate; they end up locked inside and become passengers when the craft lifts off. The tension is clear from the start as desperation and curiosity collide with a dangerous mission that could reshape their fates.
During the flight, a meteor shower injures Dirk fatally. On his deathbed he asks Steve to stay on course, hands him a medallion, and tells him to seek forgiveness from the Lido K.T. Stevens, the Moon’s enigmatic queen. With Dirk gone, the crew must navigate the unknown together as the journey toward an alien world accelerates and the truth about Dirk’s vanished past begins to unfold. The sense of unease grows as the ship hurtles toward an uncharted horizon, and the medallion becomes a constant reminder of a debt to be paid.
Upon landing, the four crew members don space suits with oxygen regulators and are immediately assaulted by rock monsters impervious to bullets. They retreat into a cave, light a torch, and discover that the Moon does have pockets of breathable air, enough to remove their helmets and continue exploring. A mysterious gas in the cave knocks them unconscious, and they awaken in an underground community of beautiful women. Steve is brought before the queen, the Lido, who believes he is Dirk and welcomes him as a returning figure who promises a glimmer of salvation for their oxygen-starved world. The sense of wonder is tempered by a growing fear that Dirk’s old loyalties may be resurfacing in unforeseen ways.
Gary ventures into the Moon’s society and quickly learns there is a diamond mine awaiting exploitation. In the palace, Steve explains to June that Dirk left Earth years ago to return with a ship capable of aiding them, but the disclosure raises questions about motive and trust. To secure their survival, June fears Lido’s discovery of Steve’s true identity, so a delicate ruse is crafted: Alpha, one of the Moon’s blonde Moon girls, is arranged to marry Steve. Alpha enters the room, kisses Steve, and the tension between loyalty and desire becomes an explosive point of conflict. June lashes out in a hair-pulling clash with Alpha, who reveals a calculating calm even as she faces a direct challenge to her authority. Alpha’s deception is exposed, but she still insists on the marriage, triggering a power struggle that shakes the Moon’s political foundations.
In the palace’s shadowed corridors, Alpha’s bid for control leads to a lethal confrontation: she kills Lido and seizes the throne as the new queen. The ruling order fractures, and June, along with Lon, Gary, and Steve, is driven into a cave where a massive spider stalks them, heightening the peril. Zema [Leslie Parrish], Lon’s Moon ally, falls in love with Lon and decides to help the Earthbound crew, freeing them from the cave and restoring access to their space suits. A brutal struggle between Alpha and the dissenting factions culminates in Zema detonating a bomb that releases the precious Moon oxygen, allowing the astronauts to don their suits and flee toward the ship. The fate of the Moon’s air supply becomes a race against time and a test of loyalties.
Gary, drawn back to the cave by the lure of diamonds, is tragically killed in a struggle with one of the rock monsters before he can reach safety, a somber reminder of the price of greed on a world where oxygen is scarce and survival hinges on trust. As the ship prepares to lift off for Earth, June asks Steve whether she is more attractive than Alpha; his reply lands with a quiet, hopeful truth: the only thing more beautiful than her, in the end, is Earth itself. In a closing echo of sacrifice and resilience, the human will to return home prevails over the moon’s perilous wonders.
