what is the cause of zombies in train to busan
Train to Busan As the train departs, a convulsing young woman boards the train with a bite wound on her leg. She soon turns into a zombie and attacks a train attendant, who then turns into a zombie. The virus quickly spreads throughout the train. Baseball player Yong-guk, a girl named Jin-hee, who has a crush on him, and several passengers escape to another car. News broadcasts report zombie outbreaks (reported as riots) nationwide and Cheonan-Asan station was attacked by zombies so they passed it. After the train stops at Daejeon station, the surviving passengers find the city and station also overrun, and they hastily retreat back to the train, splitting up into different train cars in the chaos. The conductor restarts the train to head to Busan, where a quarantine zone has reportedly been established.