Train to Busan

Seok-woo, a cynical workaholic and divorced father in Seoul, messes up a birthday present for his estranged daughter Su-an, and misses out on her recital of the Hawaiian folk song "Aloha ʻOe". He agrees with Su-an to take her to see her mother Na-young in Busan.

The next day, they board the KTX 101 for Busan at Seoul Station, along with blue-collar worker Sang-hwa and his pregnant wife Seong-kyeong, high-ranking executive Yon-suk, a high school baseball team including player Yong-guk and his cheerleader girlfriend Jin-hee, elderly sisters In-gil and Jong-gil, and a traumatized homeless man. Just before departure, a scraped up woman boards the train unnoticed at the last minute. News reports reveal that an outbreak is occurring across the country, and the scraped up lady then turns into a zombie.

She bites and infects a train attendant, sparking a rapid outbreak on the train. The survivors flee to other carriages on both sides of the train and secure the doors, trapping the hordes of zombies in the process. The train passes through Cheonan station, passing through more zombies attacking people. The conductor is instructed to stop at Daejeon Station, where a group of soldiers were deployed to keep the infection at bay. Seok-woo was also told that his company had sent an extraction team to another part of the station to pick up him and Su-an. After stopping at Daejeon, the passengers disembark from the train, but find that the deployed soldiers, including the ones from Seok-woo's company, had also fallen to the zombies. The passengers flee back to the train, becoming separated again into different carriages in the commotion. Some passengers, in a rush to get back on the train, didn't notice the zombies behind the doors before opening them, becoming infected shortly after.

The conductor cancels all future stops except for Busan, where the army has established a quarantine zone. Seok-woo, Sang-hwa, and Yong-guk sneak and fight through the zombie horde to reunite with Su-an, Seong-kyeong, In-gil, and the homeless man in another carriage. They struggle toward the front carriage, where the remaining passengers have taken shelter. The remaining passengers, fearing that the survivors are infected, refuse to let them in. Bitten in the confusion, Sang-hwa tells Seok-woo to look after Seong-kyeong and sacrifices himself to buy the others time to force open the door, but In-gil is left behind in the process.

Yon-suk, train attendant Ki-chul, and the passengers demand that the survivors isolate themselves in the front vestibule. Jong-gil, distraught over her sister's death and disgusted by the paranoid and ruthless behavior of the other passengers, opens the door to let the zombies in and kill everyone in the carriage. Seok-woo learns from an employee over the phone that his company was indirectly responsible for the outbreak. Yon-suk and Ki-chul escape by hiding in the bathroom.

A blocked track at Dongdaegu Station forces the train to stop, and the driver disembarking to search for another train, and Yon-suk escapes after pushing Ki-chul into the zombies. A flaming locomotive barrels in and crashes into some of the zombie-filled passenger carriages. Seok-woo, Su-an, Seong-kyeong, and the homeless man get trapped beneath a toppled carriage. Yong-guk and Jin-hee get split up from the party and are used as bait by Yon-suk, as he escapes for the new train. The conductor starts up another train on a separate track and tries to help an injured Yon-suk, but is mauled in the process. Seok-woo, Su-an, and Seong-kyeong find their way out from under the carriage after the homeless man sacrifices himself.

Seok-woo, Su-an, and Seong-kyeong board the new train, only to find an infected Yon-suk, who desperately begs them for help before turning into a zombie. Seok-woo manages to push him off the train, but his hand is bitten during the tussle. In his last moments of consciousness, he puts Su-an and Seong-kyeong inside the engine room, tells Seong-kyeong how to drive the train, says goodbye to Su-an, who begs him to stay. Seok-woo, before succumbing to the infection, runs to the back of the train and reminisces about Su-an's birth before throwing himself off the train.

The surviving pair arrive at a blockade of corpses and barbed wire outside a tunnel near Busan, both walk through the tunnel, with Su-an singing "Aloha 'Oe" to calm her nerves and pay tribute to her father. Su-an and Seong-kyeong are met by the army, who brings both of them to safety.