| Director | Alec Gillis |
|---|
In 1982, a Soviet moon lander crashes into the Bering Sea. In 2015, biology professor Stephen and graduate students Ronelle and Sadie go on an experimental tour to study the effects of global warming on whales. Sadie's grandfather, Graff, takes them to sea in his fishing trawler Harbinger, crewed by Bowman, Roland, Big G, Dock, Svetlana and Atka.
One night, Sadie is awakened by the crew working and their equipment detects whale activities in the area. After trying unsuccessfully to wake the others, Sadie investigates on her own. With Sadie operating the sonar equipment and the crew's help, they discover and retrieve the crashed lander, encased in ice. Ronelle and Stephen are awakened by the commotion. Stephen claims ownership of the lander, but Graff disputes this and declares it belongs to Sadie.
Bowman encourages Sadie to investigate the lander before Stephen can claim it for himself. While Big G distracts Stephen, Sadie inspects the lander and discovers the Soviet cosmonaut died of an unknown infection, taking a skin sample to analyze. Learning Sadie had examined the lander before him, Stephen becomes frustrated and threatens to destroy her career unless she signs over the discovery to him. Graff threatens to take the issue to the courts, but Sadie gives in. Sadie later learns that the lander was carrying tardigrades, a hardy terrestrial life-form that can survive in extreme conditions. However, cosmic radiation caused them to mutate and become capable of shapeshifting.
After the cosmonaut's body goes missing, Stephen examines the lander and becomes contaminated with the tardigrades, and the reanimated cosmonaut's body kills Roland. Stephen begins stripping on deck despite the sub-zero temperatures. As the others drag him back in, stalks sprout from his back and spray a dark liquid over everyone. Sadie confirms that they are all potentially contaminated. The group use liquid nitrogen to freeze Stephen's body and the lander.
When Dock begins to show signs of infection, Svetlana locks him in a cage and prepares to incinerate him. The others object to the plan until Dock also sprouts tentacle-like growths. The ship's power gets cut, and the backup battery kicks in. As they work to restore it, the organism kills Atka, during which Svetlana is revealed to be a Russian spy. Holding Sadie, Bowman, Big G, Ronelle and Graff at gunpoint, she explains that the tardigrades were part of a Soviet experiment to create radiation-resistant cosmonauts. She intends to sink the boat after boarding a nearby Russian submarine. Before she can kill everyone, however, the organism attacks, dragging off Ronelle and Svetlana.
Survivors Graff, Sadie, Bowman and Big G search for explosive charges that Svetlana has hidden throughout the boat. The last four charges are hidden in the bilge, a tight area which only Sadie has access to. As she collects the explosives, the others discover that the tardigrades consumed and absorbed their latest catch, two tons of crab. They call down to warn Sadie, who realizes she is standing amid the tardigrades and escapes in time, but Graff is infected. He instructs Big G to restart the boat and Sadie to pilot it before asking Bowman to kill him.
Big G restarts the ship but is killed by the mutated Svetlana. Before Bowman can freeze Graff with the liquid nitrogen, the creature impales him. Graff instructs Sadie to scuttle the boat and save herself. She steers it toward an iceberg and escapes while the creature bursts through the deck. Via the portable radio, the US Coast Guard alerts her that a rescue helicopter is in her vicinity. The helicopter approaches as Sadie passes out and lies motionless on the ice.