Zaat

In his laboratory, Dr. Kurt Leopold finalizes the ZaAt formula and injects himself with it. He submerges in a tank and emerges as a catfish-like monster. The transformation marks the birth of his aquatic-hybrid power.

Leopold releases walking catfish into the town's lakes and rivers, spreading chaos through the waterways. He also dumps ZaAt into the municipal water supply, sickening many residents. The town's daily life is upended by the bioweaponized creatures and contamination.

Sheriff Lou Krantz and marine biologist Rex Baker begin investigating the odd catfish activity and unusual events along the local waterways. They search for a link between Leopold's experiments and the disturbances. The investigation grows as new sightings appear.

Leopold stalks and murders his former colleague Maxson and Maxson's family aboard a boat. The killings demonstrate the doctor's willingness to eliminate anyone who mocked his work. The incident marks a violent escalation of his vendetta.

Leopold tracks down his associate Ewing and kills him in his own home. The act cements his ruthless pursuit of those who doubted him. The body count climbs as the doctor tightens his grip on the town.

Leopold abducts a young female camper at a lake and drags her back toward his laboratory. The kidnapping signals the next step in his plan to claim a mate. The town remains unaware of the looming danger.

Back in the lab, Leopold straps the captive into a mesh basket beside a large water tank. He intends to subject her to the transformative process with ZaAt. The scene sets up the climactic confrontation between science and resistance.

The equipment malfunctions as the captive struggles, and her corpse, partially transformed, is pulled from the tank. The failure underscores the danger and unpredictability of Leopold's experiments. Rex and Lou's investigation grows more urgent in the wake of the disaster.

Rex contacts a mysterious organization named INPIT, which dispatches scientists Martha Walsh and Walker Stevens to investigate. Their arrival signals official interest and escalation in solving Leopold's threat. The analysts begin tracing Leopold's radioactive trail.

Leopold kidnaps Martha Walsh, prompting a renewed urgency from Rex, Lou, and INPIT agents to locate him. The abduction raises the stakes as the investigators close in on his lair. The clock ticks toward a final confrontation.

Leopold heads toward his laboratory with Martha, followed by Walker Stevens who has tracked him. Rex and Lou converge on the lab, leading to a tense standoff. Inside, Leopold prepares Martha for her own transformation.

Lou is killed attempting to capture Leopold outside the lab, while Rex is seriously wounded inside. Leopold injects Martha with ZaAt and readies her for dunking into the tank. Rex dies after a desperate rescue, and Martha, now in a trance, follows Leopold into the sea.