Sin Nombre tells the story of Sayra (Paulina Gaitan), a teenager living in Honduras, and hungering for a brighter future. A reunion with her long-estranged father gives Sayra her only real option - emigrating with her father and her uncle into Mexico and then the United States, where her father now has a new family.
Meanwhile, Casper, a.k.a. Willy (Edgar Flores), is a teenager living in Tapachula, Mexico, and facing an uncertain future. A member of the Mara Salvatrucha gang brotherhood, he has just brought to the Mara a new recruit, 12-year-old Smiley (Kristyan Ferrer), who undergoes a rough initiation.