Marine Captain Jung-seok is driving his elder sister, her husband Chul-min and his nephew Dong-hwan to a ship leaving South Korea, which is being swept by a zombie outbreak. On the way, he encounters a family with a young child who needs a hitch, but he ignores the family's pleas and drives away. In the cabin of the ship, an infected man turns into a zombie and infects numerous people, including Dong-hwan. Jung-seok then unwillingly decides to leave Dong-hwan and his mother behind and stops Chul-min, who returns after getting some supplies, from entering the cabin.
Four years later in Hong Kong, a guilt-ridden Jung-seok, with Chul-min and two other Koreans, are briefed by the Hongkongers of an operation that requires the four to return to Incheon in the quarantined peninsula and retrieve an abandoned food truck which contains bags of cash totaling US$20 million. The four arrive the following night and after some searching, they find the truck. The four escape the area unharmed with the truck, as zombies begin chasing them.
On the way back to Incheon Port, the four are ambushed by a rogue militia Unit 631, led by Sergeant first class Hwang. Jung-seok gets thrown out of the truck, while Chul-min hides inside the truck. The other two die from the ambush. Jung-seok is then rescued by two sisters: Joon, who drives the car out of the scene, and her younger sister Yu-jin. The three arrive at a hideout, where the children live with their mother Min-jung and grandfather Elder Kim. Jung-seok suddenly realises that Min-jung is the lady that had asked for a hitch four years ago.
The truck, taken by Unit 631, arrives at the militia's compound. Chul-min is then found inside and becomes a captive. Private Kim and Captain Seo subsequently discover the bags of cash in the truck, then secretly hatch a plan to get themselves out of the peninsula with the truck, keeping their escape plans a secret from the belligerent Hwang. Meanwhile, Min-jung learns from Jung-seok that there is a ship at Incheon Port waiting to extract him. She then decides to steal the truck from the compound so that the five of them (Min-jung's family and Jung-seok) escape the peninsula together.
The following evening, near Unit 631's compound, as Joon, Yu-jin, and Elder Kim wait in the car, Jung-seok and Min-jung sneak inside, where they discover the truck and encounter Private Kim. Jung-seok realises from Kim that Chul-min is alive in the compound and moves to rescue him. Inside, Jung-seok kills zombies and several Unit 631 soldiers, but Chul-min is killed by Hwang. Jung-seok is then saved by Min-jung and the two quickly escape the compound with the truck. Numerous Unit 631 soldiers, including Hwang and Seo, give chase. In the ensuing chase, Jung-seok deliberately shoots and shatters the glass tunnel, freeing the horde of zombies inside, which then quickly attack Hwang's vehicle, killing Hwang and his driver.
The five reach Incheon Port, where Seo rams his vehicle into Joon's car, then holds her at gunpoint. Elder Kim is fatally shot by Seo as he protects Yu-jin. Seo shoots Min-jung in the leg and escapes with the truck. He drives the truck into the cargo hold of the ship, but is then brutally shot by the Hongkongers. Bleeding out, Seo reverses the truck to prevent the cargo hold's gate from closing, allowing zombies outside to enter and kill everyone inside.
The grieving four then spot a United Nations military transport helicopter and direct it to land on the port. An injured Min-jung requests that Jung-seok bring Joon and Yu-jin to the helicopter, while she clears the path of zombies. Min-jung then traps herself in a truck and presses on the horn repeatedly, intending to lure the zombies to her and sacrifice herself for the three to escape. Recalling an angry claim Chul-min made in Hong Kong that Jung-seok did not do his best to save their family four years ago, Jung-seok returns and kills the zombies trapping Min-jung. She quickly makes the run to the helicopter, and Jung-seok covers her by shooting the zombie hordes. The four board the helicopter and escape the peninsula.
Oh Train to Busan 2, still waiting for that movie, but actually I already saw the trailer and it was good.😆