Darkness, it is remarked more than once in No Place on Earth, is feared as the realm of demons, danger and the unknown. From our ancestors’ Quest for Fire and in "A Night on Bald Mountain" and the Lord of Darkness of Legend, light of fire or sun has dispelled night and brought comfort. But, long before and much longer than the Chilean miners, thirty-eight survivors in this true story praise the scarcely lit underground hell that was a heaven which allowed them to live on.

At first a mystery unraveled by its discoverer and narrator Chris Nicola, the eighty-four minutes manages to convey suspense in a tale whose outcome is already a given. Of at least equal importance, however, is that director-cowriter-producer Janet Tobias has tweaked the over-proliferating documentary form by skillful handling of current footage, unobtrusive-color recreations, minimal archival b&w and unadorned talking heads, all kept short and melded nicely one into another to give a sense of continuity in action and idea.

Only incidentally, and outside its purposes, does the film allude to, but not dissect, European anti-Semitism so ingrained that the entire war and the Holocaust make not a dent in it even though fewer than five percent of Ukraine’s vital Jewish population made it through and none remain in Korolowka village or any other.

The genesis began with “Off the Face of the Earth,” a National Geographic Adventure Magazine piece about, and with the cooperation of, Nicola, whose physical presence and New York City accent are together the film’s guide. A state investigator to finance a twenty-year enthusiasm for speleotology, scientific study or exploration of caves, in two of the world’s largest gypsum caves he came across artifacts that led to researching and locating, not his own family as he had once thought to do, but others with their memoirs and memories. Then, in Montreal, Florida and in and around New York, he met fourteen of those who had made it out.

In western Verteba and Priest’s Grotto, he had first found items like a comb or cup, buttons and shoes, a millstone too heavy to carry, not from “cave men” but the twentieth century. Nearby residents were not forthcoming and “no one even smiled” but finally admitted that “maybe some Jews lived in the caves.”

This meant hiding from the Nazis and their Romanian allies and from their own neighbors and perhaps later from Russian “liberators.” Before reading accounts published -- We Fight to Survive -- and in manuscript, Tobias had the luck of an invitation to accompany Nicola on his return trip to the site with members of three generations of the families involved, from feisty nonagenarians to their grown grandchildren.

Filming these sprightly oldsters descending into caverns at present grown more difficult to enter and recording their impressions two-thirds of a century afterwards and, later, their headshot interviews filled with precise never-faded details, was an unusual way to start, reversing what would seem the normal order.

Only then, though Tobias “knew right from the beginning that we needed to do a dramatic reenactment [and] that a classic vérité should not be the whole,” did the rest follow. For such, the original caves are of such difficult access for crew and equipment -- e.g., Priest’s Grotto is twenty meters down, reachable only by a narrow enclosed ladder -- that, instead, the Continent’s largest stalactite cave, Aggtelek National Park’s Baradla, was chosen and local Hungarian actors and amateurs played the various Stermers and Dodyks of 1942.

Darkly and finely intercut into the rest, the characters rescue family left hidden aboveground, lose others to Gestapo who enter the first hideout and capture some of them, see a mother and brother shot before their eyes, are informed on by a villager, forage for food, fuel and water, while living underground for a record five-hundred-eleven days. At reports of the Germans’ defeat and retreat, they emerge, wondering at the daylight and open space.

They had felt free in the dark, even if townsfolk discovered their refuge and plugged up the entrance. No one welcomed them back, and, confronted with continuing discrimination and violence in their homeland and German DP camps, they immigrated from the Old World to the New, exiles yearning to breathe free.

(Released by Magnolia Pictures and rated “PG-13” by MPAA.)