On a harrowing journey aboard a Vista Airlines flight from LAX to Los Cabos, disaster strikes when the aircraft collides with a flock of birds, leading to a catastrophic crash into the vast expanse of the Pacific Ocean. Tragically, the incident claims the lives of both pilots along with several passengers. Among the few who manage to survive are Ava, the daughter of a high-profile politician, her boyfriend Jed, his friend Kyle, a young girl named Rosa who is traveling with her grandparents (her grandmother survives), the steadfast bodyguard Brandon, and the resourceful flight attendant Danilo. The survivors find themselves trapped in an air pocket located at the rear of the sinking fuselage, slowly descending into the cold water beneath.
Initially, Brandon assumes a leadership role, instructing the group to remain still and wait for rescue. However, as he attempts to retrieve an oxygen tank from the front of the submerged plane, disaster strikes again when a ferocious tiger shark breaches the fuselage, attacking him in a gripping encounter. While he manages to return to the safety of the survivors, the shark soon claims him, dragging him underwater in a chilling twist of fate.
In the midst of this chaos, Kyle suffers a severe arm injury from the initial crash, prompting Rosa's grandmother, Mardy 'Nana', a former army nurse, to step in. She skillfully tends to his injury using materials salvaged from the aft galley. Meanwhile, a rescue crew commences a frantic search for the downed plane, deploying helicopters to comb the waters above. The remaining survivors engage in a heated discussion regarding their next steps, collectively brainstorming strategies as they remember Brandon's leadership suggestions. Ava calculates they have merely three to four hours of breathable air remaining, while Jed warns that the structure of the fuselage may potentially collapse, trapping them in a watery grave. Their predicament worsens as the wreckage slides down a rocky incline, plunging them further into the ocean and positioning them precariously on the edge of a dark underwater abyss.
Facing despair, the survivors make the courageous decision to abandon the aircraft and attempt a swim to safety. Rosa cleverly notes that sharks are deterred by air bubbles, inspiring the group to use their inflatable life vests to create a protective barrier. With determination, they scour the remnants of the plane in search of diving gear. At that moment, the rescue helicopter spots debris from their flight on the ocean's surface. Two rescue divers plunge into the depths to investigate but are caught off guard by the same relentless shark, resulting in a frantic attempt to warn them of the lurking danger. In a horrific turn, one diver is violently snatched away while the other disappears into the inky blackness.
As hope wanes, the survivors desperately search for the missing diver, only to be accosted by the shark once more. In a brutal encounter, Jed suffers a horrible injury, losing his leg below the knee. He quickly succumbs to shock and dies, leaving the group in mourning. Ava manages to find a bag of scuba gear among the wreckage, and the remaining survivors undertake the arduous task of planning their escape. Kyle reveals his crippling fear of deep water, reminiscing about a childhood experience that left him terrified. Ultimately, the group rallies around him, convincing him that he must summon the courage to leave the plane.
As they attempt to navigate out of the submerged fuselage, a critical moment arises when the damaged cockpit breaks away and plummets into the darkness below. Nana selflessly instructs Ava to look after Rosa, imploring her to forsake her own escape so as not to hinder the others. In a tense and heart-pounding moment, the survivors make their final push through the wreckage, only to come face-to-face with the relentless shark once again. Drawing upon their resourcefulness, Ava uses the bubbles from her life vest to create a diversion, temporarily confusing the creature and allowing them to break free.
However, tragedy strikes once more when Kyle takes a final inhalation of air just before being brutally attacked by the shark, sacrificing himself so that the other survivors might have a chance at escape. As Ava floats to the surface, she and the remaining survivors employ the oxygen tank from the missing diver to fuel their ascent. Giving the two oxygen tanks she retrieved to Danilo and Rosa, Ava prepares to make her escape from the threatening wreckage. A final encounter with the shark ensues as she spots it on a direct collision course with her, but through sheer determination, she exits just as the shattered remains of the aircraft surrender to the depths below.
Awakening on the ocean's surface, surrounded by nothing but the endless horizon, Ava fights off a wave of despair, discovering Rosa's beloved stuffed animal floating nearby, while the other survivors remain missing. Just as hope seems lost, a rescue helicopter comes into view, snatching her from the clutches of the sea. Onboard, she finds the solace of Danilo and Rosa, both of whom cling to their shared survival. When the pilot inquires if anyone else made it out, Ava shakes her head, encapsulating the finality of their ordeal. As the chopper rises into the sky, Rosa tosses her stuffed animal back into the ocean, a poignant tribute to her grandparents and the fallen passengers, as they embark on a journey toward safety, sorrow, and new beginnings.
