Geneticist Nathan Sands, [Eric Roberts], and his daughter Nicole Sands, [Sara Malakul Lane], are hired by the U.S. Navy to develop a new weapon: an intelligent shark with octopus-like tentacles, named S-11, controlled by electromagnetic pulses delivered through a head-mounted device. The initial work seems to push science forward, but during a test, S-11 discards the device and slips into Mexican waters in search of food.
To track and capture the creature, Sands and his team travel to Mexico and team up with local fishermen, [Kerem Bürsin] as Andy Flynn and [Julian Gonzalez Esparza] as Santos. Together they navigate coastal currents and warnings, hoping to outmaneuver a predator that's already begun to stalk the shoreline.
A parallel sequence follows a news crew led by Stacy Everheart, [Liv Boughn], and Bones, [Héctor Jiménez], who arrive after fisherman Pez shares a chilling photo of the creature. Stacy pieces together that S-11 is the product of a biological experiment, and the team records several fatal encounters along the beach before venturing farther into the ocean to gather more evidence.
Andy and a group of divers descend into a cave to locate the monster; the creature strikes, killing nearly everyone except Andy. He, Nicole, and Santos later encounter Stacy, Bones, and Pez; Pez is killed by S-11 before the creature disappears again. The pursuit continues as Andy, Nicole, and Santos push forward to bring the threat to heel.
Tensions rise when Andy radios Sands with a personal vow to destroy the creature, despite orders. The chase moves to the mainland, where S-11 claims more lives and Sands’s team suffers losses; Sands himself dies while trying to protect Nicole. The remaining allies—Nicole, Andy, and Santos—drive the confrontation toward a final showdown at a resort under attack by the creature.
Back at the resort, Nicole conceives a plan to shoot S-11 with a device that will enable her to overload a brain chip in the shark’s head by hacking into its circuitry. The group endures a brutal sequence where Bones quits and Stacy faces danger in attempting to film the events, only to be killed along with Bones. With time running out, Nicole executes the hack while Andy handles the onslaught, and the device is deployed to destroy the chip.
In the climactic moment, Andy fires the device and Nicole completes the overload, causing S-11 to explode in a deadly feedback that ends the threat. In the aftermath, Andy and Nicole, shaken but relieved, walk away to safety, having survived a perilous collision of ambition, science, and nature.
