Student Academy Award winner Cary Joji Fukunaga makes his feature directorial debut with this epic dramatic thriller following a Honduran teenager who reunites with her long-estranged father and attempts to emigrate to America with him in order to start a new life. Inspired by the director's firsthand experience with Central American immigrants, Sin Nombre opens to find dejected teenager Sayra (Paulina Gaitan) biding her time in Honduras while dreaming of a brighter future. Upon reuniting with the father she hasn't seen in years, Sayra seizes the opportunity to finally make her dreams a reality. Her father has a new family in the United States, and he's preparing to travel with her uncle to Mexico, where they will then cross the border to freedom. Meanwhile, in Mexico, Tapachula teen Casper (aka Casper, played by Edgar Flores), has gotten caught up with the notorious Mara Salvatrucha street gang. He's just delivered a new recruit to the Maras in the form of desperate 12-year-old Smiley (Kristyan Ferrer), and though the youngster's initiation proves particularly rough, she adapts to gang life rather quickly. As involved as Casper is with the Mara, he does his best to keep his relationship with girlfriend Martha Marlene (Diana Garcia) a secret from the gang. Just as Martha encounters ruthless Mara leader Lil' Mago (Tenoch Huerta Mejía) and suffers a grim fate at the hands of the gang, Sayra and her relatives arrive at the Tapachula train yards and prepare to rush a U.S.-bound freight train with a horde of other immigrants. Rather than attempting to gain access to the cars, Sayra and the rest of the immigrants decide to ride atop the train. Little do they realize that their lives are now in danger, because Lil' Mago has recruited Casper and Smiley to rob the immigrants as they make their way to the United States. When dawn comes and Lil' Mago makes his move, Casper finally decides to stand up to the tyrannical gang leader. Now, as the train winds though the Mexican countryside, Sayra's only hope of surviving the journey and making her way to a new beginning is to align herself with Casper as he flees from the most feared gang in Tapachula.