After the devastating events in Train to Busan and Peninsula, the remnants of humanity are fighting to rebuild society amidst a world still plagued by the zombie apocalypse. A young scientist, Minseo, discovers a potential cure hidden within the blood of those immune to the infection. However, the only way to produce the cure is to reach a secret research facility located in Busan, the original ground zero of the outbreak.
A group of survivors, led by a former soldier named Jaehyun, agrees to escort Minseo on a perilous journey through the zombie-infested landscape. Among them is a mysterious woman, Sohee, whose dark past might hold the key to salvation—or doom. As they travel aboard a makeshift armored train, tensions rise not only from the hordes of the undead but also from internal conflicts within the group.
With time running out and betrayal lurking in the shadows, the survivors must confront their deepest fears and make unthinkable sacrifices to bring hope back to humanity. Can they overcome the horrors of the undead—and the darkness within themselves—to finally redeem Busan?
