Earth’s International Space Order prepares for its inaugural Moon landing, aiming to claim the satellite as international territory. The Lunar Eagle 1 crew consists of 12 scientists from around the world—ten men and two women—accompanied by a small menagerie that includes two cats. The ship is commanded by Capt. John Anderson, Ken Clark.
Historical and international tensions flare during the flight. Dr. Feodor Orloff, [Tom Conway], is quick to boast that all scientific breakthroughs were invented by the Soviets, while Dr. David Ruskin, [Richard Weber], an Israeli astronaut, warns that the USSR would be unwise to press its influence on Israel as it did to his homeland. Ruskin admires fellow astronaut Dr. Erich Heinrich, [John Wengraf], unaware that Erich’s father was the Nazi responsible for killing Ruskin’s family—an irony that weighs on their budding friendship.
After a perilous 27-hour voyage, Lunar Eagle 1 lands and the crew begins their Moon exploration. Dr. Sigrid Bomark, [Anna Lisa], and Dr. Selim Hamid, [Muzaffer Tema], discover an air-filled cave and, after removing their space helmets, share a charged kiss. They move deeper into the cave, but the opening is suddenly sealed by an impenetrable layer of ice.
The others uncover mineral-rich rock, and when they test a rock formation with a mortar, liquid bubbles forth. Feodor rushes to the flow and suffers severe burns as his hands are burned by the strange liquid. On the return to the ship, one crew member sinks into lunar quicksand; John Anderson makes a valiant but ultimately unsuccessful effort to save him, nearly being pulled under himself.
Inside Lunar Eagle 1, a machine begins printing logograms. Dr. Hideko Murata, [Michi Kobi], is able to read the symbols. The message arrives from “The Great Coordinator of the Moon” and orders the crew to depart at once. It also reveals that the Moon-beings live underground and fear Earthlings will “contaminate our perfect form of harmony.” The Moon-beings express fascination with the cats, and state that they will study all Earthlings, but they also demand that the expedition’s feline companions be left behind, finding them as intriguing as humans.
Erich experiences a heart attack during the lunar ascent. As he drifts between semi-consciousness and clarity, David learns that Erich’s father was the Nazi who murdered his family. Yet when Erich acknowledges his past and dedicates himself to atonement, a fragile bond forms between them.
Near Earth, the crew witnesses the big freeze, a colossal freezing cloud controlled from the Moon that grips Canada, the United States, and Mexico in thick ice.
Erich proposes a plan to drop “atomic bomblets” into the volcanic peak of Popocatépetl to trigger a massive eruption and thaw North America. Etienne Martel, [Roger Til], sabotages the bomblets, revealing himself to be a French communist intent on freezing the world to advance his cause. He and Feodor clash; Etienne pulls a knife, John steps in to intervene, and Feodor calmly keeps him from escalating. Feodor then repairs the bomblets.
In a bold, desperate move, Erich and David pilot a suicide mission to deploy the bomblets from Lunar Eagle 1’s smaller space taxi. Popocatépetl erupts, and the continental thaw begins. A new Moon message reveals that the Moon-beings now understand Earthlings to be honorable and peaceful, and that the North Americans had been put into suspended animation before the great freeze, meaning no one on Earth was harmed. The Moon adds that Earthlings will be welcomed back to the Moon whenever they return.
With the thaw underway, Lunar Eagle 1’s crew prepares for a triumphant reentry and a hopeful return to the Moon’s embrace.
