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.

当神秘丧尸病毒持续在韩国扩散时，韩国海军陆战队大尉韩政锡带着他姐姐、姐夫哲敏和外甥东焕，幸运登上美军难民船离开沦陷的韩国。然而在航行过程中，其中一位难民受感染变成丧尸而侵袭整个船舱，政锡没能救出姐姐和外甥，仅能安慰失去妻小而崩溃的哲敏。四年后，朝鲜半岛遭到永久隔离，政锡等大部分“半岛难民”被安置于香港，但不管走到哪里都会被旁人视为瘟神，只能与从此极少联系的哲敏做黑工谋生。直到一天，他们共同被本地黑帮召去执行任务，回去半岛仁川广域市在三天内恊助寻回一辆满载美金的食物货车，承诺完成任务便可平分一半现金。

Empat tahun selepas peristiwa Train to Busan, seluruh Korea telah ditinggalkan, dan yang tinggal hanyalah geografi, zombi, dan keruntuhan Korea Selatan. Sekumpulan tentera laut dalam misi pencarian terperangkap di dalam dan mula menyaksikan sesuatu yang akan menguji nasib dunia.