The film begins with the Russian space station Mir exchanging communications with Akademik Vladislav Volkov, a research ship in the South Pacific. Suddenly, an enormous electrical storm from deep space strikes Mir, disrupting its electronics and sending a surge towards Earth that disables the ship. Tragically, Mir's crew seems to perish, and the fate of the research vessel's crew remains uncertain.
Fast forward seven days, during a fierce typhoon, the tugboat Sea Star, helmed by Irish captain Robert Everton (Donald Sutherland), faces a devastating loss when its cargo is changed to a pile of debts. The crew, including the capable navigator and former Navy officer Kelly Foster (Jamie Lee Curtis) and engineer Steve Baker (William Baldwin), discovers alarming leaks in the engine room. Foster proposes they seek refuge in the eye of the storm to make crucial repairs, and Everton reluctantly agrees. However, he wrestles with despair, contemplating suicide, when suddenly the Akademik Vladislav Volkov appears on their radar. Seeing the potential for a lucrative salvage operation, Everton eagerly directs his crew aboard.
Upon arrival, they find the ship eerily quiet, with all communication devices destroyed and disturbing bullet holes scattered throughout the interior. It becomes evident that a violent struggle has occurred, and with no crew in sight, Everton begins to fantasize about the immense profits that await him if the salvage is successful. He quickly sends Steve and another crew member, Squeaky ([Julio Oscar Mechoso]), to restore power on the ship; but before long, calamity strikes as Sea Star's anchor inexplicably drops, plunging the vessel into chaos and leading to the loss of crew members Hiko ([Cliff Curtis]) and first mate J.W. Woods, Jr. ([Marshall Bell]).
As chaos unfolds, Foster tends to Hiko’s injuries in the sick bay, only for a figure in a gas mask to unleash a barrage from a Skorpion 61, targeting the crew. With quick thinking, Steve subdues the attacker, unveiling the Chief Science Officer Nadia Vinogradiya ([Joanna Pacula]), who is revealed as the last survivor of the Russian vessel’s crew. In a fit of hysteria, she warns about an ominous force that requires power to traverse the ship, striking Everton in the process.
As Squeaky grows silent, Steve ventures into the engine room, commanding Woods and crewman Richie Mason ([Sherman Augustus]) to accompany him. Their expedition leads them into encounters with a menacing cyborg and bizarre machine creations. When collisions inevitably occur, the crew learns that they are up against a formidable adversary—a highly intelligent life-form that has usurped the ship and is using its machinery to hunt down the crew.
Everton's paranoia escalates when he suspects Nadia of treachery, particularly when he discovers that the alien entity has claimed power over the ship and its former crew members, turning them into cyborgs. The return of an aggressor in the form of a resurrected Squeaky heightens the urgency to tame both the alien presence and the malfunctioning ship. As the crew pieces together this strange reality, they recognize they must deploy their wit and strength to not only survive but to combat the very force that threatens them.
In a desperate attempt to outsmart the alien intelligence, they conceive a plan to destroy it, leading them to a confrontation that tests their resilience as they navigate the treacherous corridors of the vessel. However, the stakes are incredibly high as Everton’s greed leads to betrayal, culminating in an explosive climax where sacrifices are made, revealing the true cost of survival against a nightmare that refuses to yield.
With the climax of the storm past, and with mechanical monstrosities littered about, the surviving crew—led by a steadfast Kelly and a resolute Steve—sets their sights on a way to terminate the alien menace once and for all. As they learn of the creature's intentions to reach a target on Lord Howe Island, they devise a plan to flood the ship and create an explosion that will sink it, catalyzing a final showdown between flesh and metal.
A final sequence of explosive bravery ensues, as friendships are forged amidst the danger and the reigning terror of both the ocean and technology. In a poignant and relentless battle for humanity's fate, Kelly and Steve fight their way through to find freedom, even as the ship sinks beneath the waves, ultimately leading them toward hope in the form of salvation from above.
