In a future where a failed global-warming experiment kills off most life on the planet, a class system evolves aboard the Snowpiercer, a train that travels around the globe via a perpetual-motion engine.

A mother lives quietly with her son. One day, a girl is brutally killed, and the boy is charged with the murder. Now, it's his mother's mission to prove him innocent.

During the late 1980s, two detectives in a South Korean province attempt to solve the nation's first series of rape-and-murder cases.