Deranged 2012

Jae-hyuk is a former professor with a doctorate in biochemistry who has fallen from academic prestige to a humble role as a pharmaceutical sales representative after a disastrous stock market bet—a gamble his younger brother, Jae-pil, urged him to take. The siblings’ lives spiral further when a string of corpses starts washing up in the Han River, signaling the rise of a terrifying, brain-controlling threat: the Yeongasi, a mutant parasitic horsehair worm. As the parasites mature, those infected suffer a crippling hunger and an insatiable thirst, driving them to leap into water so the worms can emerge. The public, already shaken by the deaths, watches officials scramble for answers while the authorities try to keep pace with the unfolding crisis.

Across the country, the river-dead are appearing with shocking regularity, their bodies appearing grotesquely starved even as the mystery deepens. Scientists and health officials discover that the worms normally live in insects, but have mutated to infect humans. When the news breaks and the government warns anyone near water who shows symptoms to seek help, pharmacies are overwhelmed with desperate people seeking immediate relief. The situation deteriorates as more people jump into rivers overnight, and the corpses drift ashore each morning. The Ministry of Health identifies the worms as the culprits, and the crisis expands beyond the riverbanks into homes and bathtubs, where a man is found dead beside a worm-like creature swimming in the water. Winds of panic blow through the city as attempts with standard anthelmintics fail, bringing only pain and further tragedy.

Amid the chaos, a single drug—Windazole—appears to offer a glimmer of hope when a patient claims it cured him. The country erupts in a fevered chase for Windazole, and pharmacies quickly run dry. The government pressures ChoA Pharmaceuticals, the company behind the drug, to boost production, but the company’s recent ownership change leaves its production lines tangled and unable to deliver. Public hearings follow as officials demand the drug’s exact composition, but the CEO clings to secrecy, arguing that stockholders will not permit disclosure of the “recipe.” The investigation thickens when Jae-pil uncovers evidence that workers at ChoA orchestrated the outbreak as part of a calculated stock manipulation scheme: they released the parasite after stockpiling thousands of Windazole packets, hoping to spark a nationwide rush and inflate prices. The revelation drives the chase deeper as a former ChoA researcher confesses the full plot, naming colleagues who accelerated the scheme before its collapse.

The plot thickens when Jae-hyuk and Jae-pil reunite and confront the storage site where the remaining drugs are kept. They race against time as a locked door and a fire trap them inside, and the informant is murdered by a mysterious man—revealed later to be the very researcher who claimed Windazole had cured people. The head of the original team, a close ally of the CEO, had remained behind to oversee the unraveling of the plan, while other researchers flee overseas. The government’s bid to buy ChoA is thwarted when the Prime Minister—Prime Minister—is warned of the scam and pulls the alarm just in time, leading to the CEO’s arrest. In his moment of despair, Jae-hyuk realizes his knowledge of chemistry could be used to create a drug with the same active ingredient as Windazole, offering a viable treatment for all who are infected, even without Windazole itself. The pharmaceutical industry mobilizes, and new, effective medicines begin to circulate as society scrambles to respond to the crisis.

The family path to stability becomes a fragile beacon of hope as Jae-hyuk and his loved ones spend a day at an amusement park, dreaming of a carefree vacation where medicine and access to care are reliable. The plan to travel overseas, with the world of drugstores in view, reflects a cautious optimism in the face of ongoing fear. Yet a final, chilling twist underscores the persistent threat: a body drifts in New York Harbor, a reminder that Yeongasi may not be confined to one nation or one river, and that vigilance remains essential even as science races to outpace the disease. The film closes on this uneasy note, a testament to resilience tempered by the ever-present shadow of a threat that refuses to stay contained.