Sin Nombre is writer-director Cary Joji Fukunaga’s feature début and derives from research resulting in and from his prize-winning 2005 Sundance short about immigrants who suffocated to death in a truck in Texas. The present ninety-six minutes touch our land for end-seconds but mostly alternate between Tegucigalpa and Tapachula in Chiapas before settling into a central journey northwards.

Putting a face on illegals’ experience on the way here instead of after physical arrival, and on an important non-political factor prompting the dangerous uprooting, the film is at once informative and gripping in story and technique. Its title means “without a name,” for those who have no papers and for the estimated two million faceless refugees from the Central American isthmus.

Made twenty-six years ago, Gregory Nava’s El Norte shares an untranslated title and unhysterical compassion and acting in the midst of the violence that prompts and permeates the migration. While also in subtitled Spanish, however, that PBS American Playhouse production does have some English dialogue as well, and, at forty minutes longer, pictures the undocumented dreamers’ degradation in Southern California.

Horacio (Gerardo Taracena) returns after years, to smuggle teen daughter Sayra (Paulina Gaitan) with her uncle Orlando (Guillermo Villegas) from hopeless Honduras back up to his new wife and children in New Jersey. Repeating his home phone number in case of emergency, he marches them across mountains and borders into Mexico, whence at least the next thousand miles will be covered on top of freight trains with many others seeking the same goal, dodging police and bandits, squatting in railyards between rides, being thrown food by villagers or, feared like Steinbeck Okies, pelted with rocks.

Finances prevented actual filming from Honduras on up to the Rio Grande, but, crew safety-harnessed onto boxcars behind locomotives or tractor trailers, the seven-week shoot conveys the perils and camaraderie of the trip, the waiting in steam and smoke, the nights, and the noises.

Joining them but at first ostracized by the gentle frightened “wetback” hopefuls, is Casper (Edgar Flores), who trails a second, little known, story thread. The sole gang member to give a real name, and that only later -- Willy -- he belongs to the Mara Salvatrucha, initially formed to protect Salvadorans from ethnic and racial violence in Los Angeles but grafted throughout Central America following deportations from the U.S. The estimated fifty-thousand-strong Mara web encompasses most every nasty business imaginable. Tattooed more than NBA players, with their own argot and “devil’s-head” hand signs, its “families” cooperate with and war on each other, but all abuse their Third World compatriots.

Different in dress and markings from his cohorts, Casper is a favorite with local warlord Lil’ Mago (Tenoch Huerta Mejía) and introduces his protégé El Smiley (Kristyan Ferrer), who is kicked for a count-of-thirteen initiation. The twelve-year-old’s wide smile through blood and pain now, and then later when his inside lip is tattooed, is an indication of the youngster’s character and final action.

Casper has hidden his gentle love affair with Martha Marlene (Diana García) from the immoral right-makes-right brotherhood, but, with disastrous results, she shows up at a Mara meeting in the cemetery. On suspicion of lying, Casper and Smiley are stripped of firearms and, as a loyalty test, assigned to accompany Lil’ Mago on a mission of theft among cowed migrants atop the trains. His girlfriend in mind, instinctively protecting Sayra and Smiley, Carper takes a decision that leads to his being hunted in his country and, through contacts, in the Promised Land towards which they are heading.

Horacio insists on survival of the blood family unit abovet all, as the sporadic journey continues, some making it while many falter. Sayra and Willy/Casper cast off symbols of the past, but alongside the rails to hope through textured fields and distant mountains, that past of despair rushes to intercept them.

The characters have names, and are not symbols, at the same time that their desperation and flight are those of millions in search of opportunity. “Oh my name it is nothin’, my age it means less,” as growing waves of migration to imagined better lives, do much to shape the world today, and each of the moving mass has his or her own story and unique face.

(Released by Focus Features and rated “R” for violence, language, and some sexual content.)