Mutiny in Outer Space

Maj. Gordon Towers and Capt. Dan Webber return to Space Station X-7 after collecting geological samples and ice from the Moon's caves. Dan collapses upon arrival and is rushed to the infirmary by Dr. Hoffman. Gordon is reunited with Faith Montaine, his girlfriend and a civilian biochemist aboard the station.

Hoffman struggles to diagnose Dan, ruling out space raptures because they cause hallucinations rather than a high fever. Faith notices a welt on Dan's leg that rapidly grows into a large fungus, suggesting the spores came from the Moon caves. Dan is placed in isolation to prevent spreading.

Col. Frank Cromwell, the station's commander, behaves oddly as a swarm of meteors closes in. He cannot issue evasive orders without prompting from Lt. Connie Engstrom, the communications officer. The moment hints that something is terribly wrong with his grip on command.

Dan dies, his body horribly disfigured by the fungal infection. Cromwell inspects the corpse and dismisses it as nothing unusual, refusing to report the death to Gen. Knowland. He claims the death was due to 'pressure shock' and warns others to keep silent about the fungus to avoid panicking the crew.

Gordon decides the situation warrants removing Cromwell from command, but Cromwell accuses him of mutiny. He orders Connie to relay a report to Knowland accusing Gordon of holding the crew at gunpoint. Connie secretly records the order, setting up later exposure.

Connie transmits the mutiny report to Knowland while also delivering news that the fungus is spreading through the station. Knowland suspects something is wrong because weapons had been outlawed for decades. The crew learns the entire station is under fungal threat.

Knowland tries to reply to X-7 but there is no response, signaling a complete break in contact. He contemplates destroying the station to prevent the fungus from reaching Earth. He recognizes the gravity of the situation as the fungal threat spreads.

Hoffman contracts the fungal infection and becomes gravely ill, yet manages to tell Faith and Gordon that the fungus can be killed by cold. This discovery becomes critical to the plan to retake control of the station. The illness heightens the urgency to counter the threat.

Gordon, Faith, and Hoffman mount a second attempt to retake X-7 from Cromwell, who is now fully under space raptures and trying to destroy the station. Cromwell is confined to his quarters, escapes, and sabotages the communications system, cutting off all contact with Earth. He is recaptured later.

The team discovers that lowering X-7's interior temperature below zero kills the fungus inside, but it begins to grow on the exterior surface due to unshielded solar heating. The mystery of exterior growth puzzles them until a staff officer suggests the sun's heat as the culprit. They begin adjusting their approach to manage the heat.

Knowland devises a plan to launch a rocket that will explode and form a cloud of ice crystals for X-7 to pass through, freezing the exterior fungus. The operation relies on manipulating orbital exposure to cold air and ice. The crew prepares to implement the solution to save the station.

The plan succeeds and the exterior fungus is killed. Gordon uses the repaired communications system to request a relief ship, and Knowland confirms it will arrive in three hours. Faith and Gordon share a relieved smile, believing the crisis is finally over.