| Director | Han Jae-rim |
|---|---|
| Genre | action film, disaster film, drama film, thriller film |
| Runtime | 141 min |
| Country | South Korea |
| Budget | ₩26 billion |
| Box office | $21.4 million |
At Incheon International Airport, a man named Jin-seok suspiciously questions a staff member about the most popular flights, and after being denied an answer, insults the staff and heads to the bathroom. There, he surgically inserts a cylindrical object into his armpit. Meanwhile, Jae-hyuk and his daughter Soo-min are also at the airport. Jin-seok later approaches them with inappropriate questions, prompting Jae-hyuk to protect his daughter and walk away. Unbeknownst to them, Jin-seok has smuggled a virus onboard their flight by hiding it inside an asthma inhaler.
Detective In-ho, investigating a viral terror threat video, traces the video back to Jin-seok and searches his home, where he finds evidence of animal testing and a decomposing corpse. Meanwhile, Jin-seok releases the virus in the airplane bathroom. A different passenger enters the contaminated restroom and later collapses from severe hemorrhaging. Jae-hyuk sees a terror threat video mid-flight and identifies Jin-seok as the perpetrator. Suspicion rises when Soo-min reveals that Jin-seok threatened to kill everyone on the plane.
Panic spreads as passengers begin showing symptoms. Jin-seok is confronted and restrained after releasing more of the virus. In the cockpit, co-pilot Hyun-soo and flight attendant Hee-jin notify the captain, but the captain succumbs to the infection, causing the plane to dive uncontrollably. Jae-hyuk, a former pilot who left the profession due to trauma from a past emergency landing, steps in and helps stabilize the aircraft alongside Hyun-soo. On the ground, In-ho pursues Jin-seok's accomplice and uncovers the virus' origin: a mutated hemorrhagic virus from the Middle East, tied to Jin-seok's dismissal by a pharmaceutical company.
As more passengers show symptoms, the U.S. and Japan deny the plane's landing request. In South Korea, public panic grows, with protests and online comments urging the government not to allow the infected flight to land. The passengers on board, realizing the severity of the outbreak, begin accepting their fate. Soo-min and others volunteer not to disembark, fearing they may cause harm to people on the ground. Jae-hyuk announces that the plane will not attempt to land.
At the last moment, an experimental antiviral drug given to In-ho shows promising results, and the vaccine's effectiveness is confirmed. The flight is granted emergency clearance to land but is low on fuel. Jae-hyuk diverts the plane to a military airstrip and narrowly avoids crashing. In the aftermath, the Minister of Land resigns, Jin-seok's sociopathy is confirmed, and the surviving passengers reunite at a celebration.