While a zombie virus breaks out in South Korea, passengers struggle to survive on the train from Seoul to Busan.

She lives with her father and a sibling. One day, her father has a mysterious accident, forces her to look after her younger sibling, the restaurant, and an investigator to find the truth about the accident.

A determined homicide detective assigned to take down a ring of serial killers, who has a personal motivation as one of the victims is his own brother-in-law.