Sin Nombre, Cary Joji Fukunaga’s harrowing first feature, is one of the most emotionally devastating films in the Festival lineup this year; it is also one of the most thrilling and emotionally redemptive. Sin Nombre, which was supported by the Sundance Institute Labs, is the story of two Central American immigrants, Sayra (Paulina Gaitan) and Casper (Edgar Flores), whose journey from Honduras, through Mexico, and into America is the same one an estimated 70,000 Central Americans take every year in an attempt to leave behind the numbing poverty of their lives. They perch uneasily on top of Mexican freight trains, and it’s far from a safe passage.