Claudia, 22, gets busted for credit card fraud and deported from USA to Mexico. She returns to her estranged dad's ranch. She's a pocha - can't speak Spanish. She gets involved with a drug smuggler.

Seven years after the world has become a frozen wasteland, the remnants of humanity inhabit a perpetually-moving train that circles the globe, where class warfare, social injustice and the politics of survival play out.