On the Space Station laboratory Project Adonis in orbit a thousand miles above Earth, Lt. Rupert Howard finds plants clinging to the wall of the space lock. He brings three specimens to the lab and incubates one, and then takes a call from Major Mike Doweling. Howard says that the spores have apparently been floating around for a million years. In the incubation chamber, unnoticed, the spore grows.
Howard takes a slide specimen of another spore, while the spore in the incubation chamber extends a flower. The lieutenant finally notices and puts the spore on the table, and jots down readings. The plant emits dozens of small spores, and Howard collects them and starts choking. When Howard goes over to the flower, it sprays dust in his face. Dying, Howard, tosses the flower in the disposal chute and staggers over to the other two spores, but dies before he can do anything.
Later, the four-man Adonis crew perform a space burial for Howard. They eject his body out into space and secure the airlock, and Lt. Gordon Halper find one of the spores caught in the outside door. The astronaut breaks it off and they take it inside.
Mike is sunbathing when Halper shows him the spore. They note that it's the third one and Mike puts the specimen in a can. Halper leaves and the artificial sunlight hits the spore, which starts sprouting a flower.
Later, Mike shows the other crew--Halper, Gavin, and Benedict--how the spore has flowered. Benedict says that they'll let the scientists on Earth figure it out. Mike asks to be stayed on Adonis and finish the work he was doing with Howard, but Benedict says that their three months is up and they'll let the next crew handle it. Colonel McWilliams calls and they go to the communication room to talk to McWilliams and Mike's wife Janet. Behind them, the spore emits gas, enveloping a lab rabbit.
On Earth at the Department of Space Travel Communication Division, Benedict informs McWilliams that they buried Howard and relates Mike's request. Janet, a technician there, takes the microphone and says that she's missed Mike. Mike hesitates and McWilliams takes the microphone and tells him to come back and Janet is waiting for her. He then says that the Pentagon wants a full report on Howard's death. Mike agrees but says that they'll have to fill in the cause of death.
Once Mike signs off, McWilliams tells Janet to check the reentry system. Once she leaves, McWilliams tells the chief surgeon Major Nathan Jennings that he made the decision not to bring Howard's body down for a full examination. Jennings says as the chief surgeon they don't know if it was some kind of alien virus. McWilliams insists that he couldn't risk the chance of infection.
The Adonis crew find the dead rabbit, its hemoglobin destroyed, and confirm that it died the same way that Howard did. Gavin reports that the shuttle is ready to go and Benedict tells him to put the spore samples in the front cabin with them since they've sealed away the rest of the specimens. The shuttle heads for Earth and when the stabilization system goes out, one of the containers with the spores breaks open. Mike puts the ship into safe orbit and then notifies Adonis Center, and leaves the ship to repair the exterior stabilizers.
While Mike works, one of the flowering spores releases gas into the interior. Benedict notices Halper sleeping, and when he wakes him Halper says that he's feeling woozy but dismisses it as the excitement of going home. Gavin says that he feels sick to his stomach, and Benedict tells them to put their helmets on while doing so himself. Mike reports that he's repaired the system, and Benedict tells him to keep his helmet on. Halper informs Benedict that he's getting weaker, and Mike enters the cabin. Benedict weakens as well, and Mike wonders why he has no symptoms when he was closer to Howard than anyone. The flowers spray spores into the cabin and then give off vapor, and Benedict tells Mike to isolate them in the aft compartment.
Benedict informs Adonis Center of what happened and confirms that Mike was not exposed to the gasses. The aft compartment is overrun with the plants and can penetrate metal with their stems, and Benedict tells them to destruct the shuttle to prevent contamination. Benedict passes out and Mike says that he's woozy and they'll maintain orbit until ordered to destruct as Gavin passes out.
McWilliams and Jennings consider what could happen if the plants are exposed to sunlight if the shuttle crashes. Jennings objects to killing the four astronauts, but McWilliams points out that Earth's population could be infected. He orders a missile and tells Janet--who has been present-- that she has as much stake in it as anyone. General Mayberry calls and McWilliams informs him of the situation. Mayberry tells him to make the decision, and McWilliams figures that if they destroy the craft then they can find more specimens in space. Janet says that if they had brought back Howard's body then they would know a way to determine how the spores destroy the hemoglobin. McWilliams tells his people to contact the replacement crew and order them to avoid any strange plant life, but then realizes that it's too late. He then tells Janet to bring the shuttle down.
Janet contacts the shuttle but gets no response. McWilliams finally gets through to the fading Mike, who says that they can't risk bringing down the shuttle. McWilliams tells him to bring the shuttle down, but Mike warns that the plants are lethal. Janet begs Mike to bring the shuttle down and comes home, and McWilliams orders Mike to bring the shuttle down. Mike reluctantly agrees and McWilliams gives him new coordinates to land at: the Springfield Missile Base in Florida. Janet begs McWilliams to let her go with him, and the two of them head to the base.
Mikes comes in six miles off-course. The emergency squads arrive at the shuttle when it crashes down. Janet stays in the car while Jennings figures that the body harnesses should have absorbed the shock. Plants have already spread outside of the shuttle. Mike responds and says that Halper is dead but he doesn't know about Benedict and Gavin. A sergeant pries the jammed hatch open, and a flower sprays him with spores. Jennings examines the soldier and confirms that he's okay, and stares at the growing number of plants. They spray spores while Jennings calls Springfield. He learns that there's a 90% chance of rain and worries that the plants will spread even faster. A flower sprays gas rather than spores, knocking the sergeant unconscious. Medics take the man away to receive a transfusion, and a flower extends into the car toward Janet. McWilliams sees it and yells a warning to Janet. She runs out as the flower sprays spores at her, and McWilliams tells her to get into the ambulance.
McWilliams gets the hatch open and Halper's body falls out. Gavin emerges next and then Benedict. Mike is last and Janet hugs him. The flowers continue releasing spores, and a storm forms as McWilliams, Mike, and Janet get to the ambulance. The sergeant recovers from the transfusions that they give him, and the ambulance heads to the hospital with the astronauts. It runs over one of the plants, which emits a bloodlike substance when its stem is severed.
The flowers continue growing and spraying spores, and McWilliams and Janet get into the car. The car won't start, and McWilliams discovers that the engine is filled with the plants. Lightning flares and McWilliams calls Jennings. Jennings says that the flamethrower squads are on the way, but warns that it will be 30-40 minutes until they arrive. Mike and the sergeant have almost fully recovered, and McWilliams and Janet try to escape on foot. The flowers have spread everywhere and release more gas, and Janet and McWilliams make their way along a railroad trestle. There are more flowers ahead, cutting off their escape route. McWilliams leads Janet into the forest. It begins raining and the flowers "whine" as they die from exposure to the rainwater. The flowers collapse, dead, and Janet realizes that a simple thing like rain has saved them. McWilliams figures that the flowers came from another planet and they look up at the sky in awe.
Written by Gadfly on Mar 9, 2019