On Vista Pacific Airlines flight 7500, a Boeing 747-300, departing from Los Angeles to Tokyo Haneda, a diverse group of passengers boards the long-haul journey. Among them are Laura Baxter, an air hoste ss; Suzy Lee, a sharp-eyed crew member; Jake, a thief with unclear motives; Lance Morrell, a suspicious businessman traveling with a mysterious wooden box; a young woman named Raquel Mendoza; newlyweds Brad Martin and Pia Martin; and Liz Lewis, flanked by the goth Jacinta Bloch. The two air hostesses, Laura and Suzy, greet the passengers as the flight eagerly ascends, while Suzy teases Laura about an off-limits, secret relationship with the married captain, Captain Pete.
A few hours into the journey, the plane encounters turbulence that soon fades, but tension lingers. Lance suffers a panic attack and unexpectedly bleeds from the mouth; shortly after, he dies, and Captain Pete presses on toward Tokyo, relocating first-class travelers to the Economy cabin and keeping Lance’s body sealed off in the empty first class. While the crew distributes drinks, Laura notices water bottles collapsing and warns everyone to strap in as cabin pressure dips. Oxygen masks deploy, yet at least one fails, and the co-pilot sinks into unconsciousness as thick smoke threads its way along the cabin floor.
When the pressure stabilizes and the smoke clears, Laura rescues Raquel from the toilet with an oxygen tank. The plane’s radio has gone quiet, cutting Captain Pete off from Tokyo air traffic controllers. Jake slips into first class to steal a Rolex from Lance’s body, but his hands tremble—and the corpse appears to move on its own. The moment he peels back the cover, he is stunned by an unseen force off-screen. Suzy discovers that both Jake and Lance’s body have vanished, raising alarms.
Laura spots an F-16 escort jet idling beside the plane and calls the cockpit, only to be met with silence and Captain Pete’s insistence that no fighter jet is in sight. On the in-flight TV, a corrupted broadcast distorts Brad’s show with a deathly image of Lance, while Liz sees a ghostly reflection of Lance on her laptop screen. Raquel heads to the washroom for a pregnancy test and breathes a sigh of relief when it’s negative, but the toilet soon fills with smoke and a hand drags her underground.
The eerie images of Lance begin to shape the passengers’ suspicions as they unzip Lance’s carry-on and discover hair tubes labeled with women's names. In Lance’s small wooden box lies a “death doll,” understood by Jacinta as a Shinigami—a being that collects souls once someone lets go of what binds them to the world. Suzy then confesses to Laura that Lance’s death makes her reconsider her own engagement, which in turn prompts Laura to end her relationship with Captain Pete.
Driven by fear and curiosity, Laura searches Lance’s checked luggage and crawls into the cargo hold through a hatch. A disembodied hand snatches her, and Suzy, awaiting by the hatch, is also seized. Suzy rushes back toward the front of the plane, but a hidden overhead compartment swallows her. As passengers scatter, Jacinta hesitantly follows a figure who reveals itself with a warm embrace, an eerie memorial to the unknown.
One by one, the remaining crew and passengers confront the truth: Captain Pete and the co-pilot lie dead in their seats, and the others discover their own bodies slumped in their rows. A breaking-news broadcast interrupts the cabin’s entertainment screen, reporting that Flight 7500 suffered catastrophic decompression and that communications were lost. The escort jet vanishes from radar, and the Boeing 747-300 drifts into ghost-plane territory. It becomes clear that the passengers and crew perished from hypoxic hypoxia during the turbulence, and that those who disappeared had let go of the thing that tethered them to the world. Brad and Pia come to terms with their fate and reconcile, even as the plane’s fuel gauge dips to zero and the aircraft plummets into the ocean.
Sometime later, Liz sits with a pale, shaken expression, her face still half-hidden. She looks up, only to find the cabin inexplicably empty once more. The unmistakable creak of the death doll echoes from a waste bin, a discolored hand emerges, and Liz braces herself for whatever comes next as the screen fades to the endless sea below.
