The world is overrun with Kabane, infected humans with an appetite for flesh. While the last of humanity has retreated into fortress-like stations connected by armored trains, some remain as hopeful as Ikoma. Servicing the trains for a living, Ikoma uses his spare time to build a weapon that could defeat the Kabane. Unapologetically optimistic, he eagerly awaits the day when he can test it. When a train is hijacked by the Kabane, he may finally get his chance. But an unexpected turn of events puts him in a situation that will test not only his weapon but his own humanity.