Ziam

Global warming drives temperatures higher, triggering a deadly bloom of bacteria released from melting polar ice, killing millions of fish. The fish that escape into the sea become unsafe for consumption, plunging world markets into a long-term food crisis. Nations brace for a crisis that is expected to last decades.

Thailand is relatively unaffected by the crisis and retains abundant food resources. VS Corporation, a multi-billion-dollar food company owned by Mr. Vasu, becomes a lifeline for the Thai population. The country’s resilience sets the stage for corporate power to play a key role in survival.

Singh, a driver, transports crates of fish for VS Corporation. Some workers salvage fish from a shipwrecked vessel, and rumors hint at a hidden lab on board where fish are bred in an artificial environment. The voyage hints at darker experiments behind the food supply.

Purich, Vasu's right-hand man, oversees the distribution of the fish to a group of men. He tastes the fish to assure its safety, and as the batch is deemed safe, the men begin turning into zombies. The scene foreshadows a dangerous flaw in the supply chain.

Rin, a nurse at Prachamit Hospital, worries about Singh's shady associations and fears he may not return. Bangkok falls into chaos with martial law as people scavenge for food, prompting Rin and Singh to plan a move back to their village in Chiang Dao and to seal their engagement.

Purich arrives at the hospital and quickly turns into a zombie, attacking hospital staff and spreading the infection. The chaos spreads as more patients and workers fall under the undead, compounding the emergency.

Vasu's wife is suffering from liver failure, and he has arranged a 'fish liver' transplant from the same batch of fish to save her. Rin discovers that Vasu is present at the hospital during the outbreak and that his scheme may be tied to the infection. The hospital becomes a focal point for greed and desperation.

With the infection spiraling, the Royal Thai Army is called in to contain the outbreak. Singh sneaks into the hospital to locate Rin and help evacuate survivors as the soldiers struggle to control the rising wave of zombies.

The army places explosives in the underground parking level to demolish the hospital and prevent contamination. A separate order arrives to evacuate Mr. Vasu and his wife, complicating the already chaotic mission.

Rin uses the security control room to monitor the hospital's feeds and learns that Vasu and his wife are inside the building. Buddy, a boy who befriended Rin, helps guide Singh to Rin by reporting that she is on the 5th floor; Buddy's mother on the 5th floor remains human for now.

Singh and Buddy finally reach Rin on the 10th floor, completing their perilous trek through the hospital. The trio consolidates their plan to escape as the outbreak continues to spread through the building.

While driving toward the city, a billboard proclaims 'Insect Farming Project For Food Security', hinting that VS Corporation may have run similar experiments to boost food production. The line suggests a possible link between the company's operations and the outbreak.

The army reaches Vasu and his wife to extract them, and they shoot Singh, uncertain if he is infected. Rin is forced to accompany the others with Vasu's wife being shifted to safety; the army unit is later overrun by zombies, and Singh is rescued by Rin and treated.

Singh fights the horde in the hospital parking lot and realizes bombs will detonate soon. He makes a last dash to the terrace, where the hospital explodes in a fiery collapse, yet he survives by diving into a water tank. A zombie opens the tank, and Singh emerges to crush its head, leaving Rin and Buddy to flee with the others.