Sok-woo is a father who does not have the opportunity to scratch his job and constantly neglects his daughter. Upon her daughter’s insistence on her birthday, she reluctantly gets on the train that will leave Seoul and go to Busan to leave her next to her ex. When the train is just about to leave, a woman affected by an unusual virus begins to spread the virus to the train. Anyone infected with the virus turns into zombies one by one. While the virus, which its cause could not be determined, is spreading all over the country, Sok-woo, his daughter and many more passengers engage in a relentless struggle for survival in the train that quickly travels to Busan.