Three teenagers—Teru Aoki, Nobuo Takahashi, and Ako Seto—discover that they are the lone survivors of a gruesome train accident that proved fatal to their fellow classmates and teachers. In an attempt to make their way out of the dreadful wreckage, they band together to grapple with hunger, loneliness, and the overwhelming sense of loss. However, as something sinister lurks in the shadows, the trio must fight off their worst impulses and the temptation to succumb to madness in these cruel times of despair.