In Dead Sea, Kaya Adams is a young woman who has been shouldering family responsibilities ever since her mother died at sea. She cares for her younger brother and tries to keep things together at home, though their lives are strained and uncertain. One day, her best friend Tessa decides to go on a jet‑ski outing with her boyfriend Julian and his friend Xander, traveling from Florida into Bahamian waters. Kaya initially hesitates but agrees, hoping for a break from her daily burdens and looking for a bit of adventure.

The outing begins promisingly, with sun, sea, laughter, and youthful connection. Kaya and Xander begin to grow closer during moments of shared vulnerability. But tragedy strikes on the ride back: Julian’s jet ski is overturned amid a riptide, Xander crashes into him, and Julian drowns. The jet skis sink, their phones are lost, and Kaya and Tessa are left stranded with a badly injured Xander, exposed to the dangers of sharks and isolation on the open ocean.

Rescue seems to arrive in the form of Rey, a fisherman who appears in a weathered fishing vessel. He brings the survivors aboard, patching up wounds and promising to radio for help. But the relief is short‑lived. It becomes increasingly clear that there is something sinister at work. Kaya and Tessa wake up chained below deck in the crew’s quarters, door locked, cries for help scrawled on the walls, evidence that others have suffered here before. What looked like rescue has become a terrifying trap.

They discover that Rey is complicit with a Dr. Curtis Hunt. The two run a horrifying criminal enterprise: victims are rescued (or lured) at sea and then turned into organ donors for black‑market auctions. Xander is harvested alive, his organs taken, and his remains thrown to the sea. Tessa is next. Kaya, witnessing this, fights to survive and protect her friend. She escapes her confinement, sabotages Rey’s boat, trails the traffickers’ operation, and readies herself for a confrontation.

As the climax unfolds, Kaya manages to shoot Hunt with a harpoon and attempts to flee. Rey pursues her, injuring her with a stab, but she summons what strength remains to fire a flare gun, and finally activates a GPS beacon that draws help. In the melee, Tessa is badly hurt and makes Kaya promise to leave her if they must in order to survive. KTShe does, dramatically escaping to reach help—though it is ambiguous how badly both are wounded.

In the end, authorities arrive, guided by the beacon. Kaya is rescued and hospitalized. Tessa, floating in the ocean with grave injuries, is also found. Though the film doesn’t give a neatly perfect resolution, Dead Sea leaves viewers shaken: it is a story about betrayal, survival, human darkness hidden beneath seeming kindness, and the resilience of those who refuse to give up, even when all hope seems lost.