People trafficker Byeong-woo (Sang-yeob Lee) contracts a mysterious illness after smuggling illegal immigrants into Bundang, near Seoul. Rushed to hospital covered in red rashes and coughing up blood, he quickly dies. But not before the airborne bird flu virus has taken hold. In less than 24 hours, this unstoppable disease is sweeping through the city. The virus has an infection rate of 3.4 people per second, there is no known cure, and death occurs within 36 hours. As Bundang is plunged into chaos, the government moves to impose a quarantine. The only hope is for infectious disease specialist Kim In-hye (Soo Ae) and rescue worker Kang Ji-goo (Hyuk Jang) to enter the closed city and develop a vaccine. A compelling tale of personal heroism against the backdrop of unimaginable suffering, this South Korean disaster movie is scarily realistic.