The compelling and quixotic true story of a British army officer who, a century ago, ventured into uncharted realms of the South American jungle in search of a presumed ancient civilization, The Lost City of Z is a rare piece of contemporary classical cinema; its virtues of methodical storytelling, traditional style and obsessive theme are ones that would have been recognized and embraced anytime from the 1930s through the 1970s. Whether they will be properly valued by more speed-minded modern audiences will only become known when this immaculate production is released next spring, a half-year after its world premiere as the closing-night attraction at this year's New York Film Festival.

Based on David Grann's 2009 best-seller, writer-director James Gray's screenplay can include only a fraction of the arcane historical and cultural information conveyed in a nonfiction book. It also refrains from going in other possible directions, such as inventing adventures that didn't happen or attaching a fashionable modern ideological agenda about the white man's incursion into a native population's turf.

Rather, it honors the spirit of physical risk, intellectual curiosity, individual daring and self-sacrifice (of both body and sanity) required to explore the unknown, to discover more about our origins and to map the world, which even 100 years ago had not been fully accomplished. Under scrutiny here was the interior of South America and the origins of the Amazon (was it fated that Amazon Studios should acquire the film's North American theatrical rights?).

One trait that seems to come with such territory is a certain obsession or wild-man gene that takes precedence over logic, personal safety and concern for home and hearth, and this increasingly pertains in the case of Col. Percival Fawcett (Charlie Hunnam). A hardy and accomplished British Army officer long posted in Southeast Asia, Fawcett comes from modest means, not the ruling class (“He's been rather unfortunate in his choice of ancestors,” one superior sniffs). Still, in the interests of mapping hitherto uncharted realms of eastern Bolivia and the imprecise border area with Brazil, the elite Royal Geographical Society backs him in launching a small expedition into an area that's a literal blank on maps of the time.

The straightforward opening stretch has Fawcett leaving behind his spirited wife Nina (Sienna Miller) in 1906 on what promises to be a two-year venture into the dense jungle with his close army comrade Henry Costin (a thickly bearded Robert Pattinson) and a tiny band of guides and porters. “Ain't nobody comes back from up there,” he's melodramatically warned by an old salt who would have fit right into a rugged 1930s Hollywood action feature.

Threats both natural and human lurk everywhere. While Gray does a lovely, low-key job of sliding the viewer, along with the explorers, from the edges of the known into the absolute wild, readers of Grann's book may miss the extraordinary inventory of excruciating jungle predators just waiting to torture tender-skinned humans, from invisible microbes and strength-sapping parasites to enormous insects, toothsome flesh-ripping fish, jungle cougars and Jurassic era-sized eels and snakes. (The young David Cronenberg could have made a whole other kind of movie based on the material Gray has largely ignored.)

What the director and cinematographer Darius Khondji do achieve, however, is an eerie ease as the group moves up the river on a small barge, then genuine shock when the explorers are caught off guard by a flurry of arrows launched by natives who look like they're stepping out of the early Iron Age. Tribes both friendly and hostile occupy the Amazonian forest and, while Fawcett never knows which he'll encounter, he develops a special confidence that he won't be harmed; before long, a certain aura emanates from the man that persuasively argues for his singular talents as an explorer.

Transforming Fawcett from a mere map-maker into an obsessive is his conviction that a great city lies buried somewhere in the jungle. Toward the end of the first journey he finds some ancient pottery and shards of other evidence for which no explanation is plausible, convincing him that he could upend all conventional notions about the history of the Americas.

But unlike Indiana Jones or Fawcett's own beloved Kipling heroes, this explorer has real life to contend with. It genuinely pains him to be away from his resilient, intellectually vibrant wife and his young son Jack, who greets him with the query, “Are you my father?” (Two more kids are to follow.) Still, finding himself now acclaimed as “England's bravest explorer,” Fawcett hatches plans for a return to the Amazon, this time not only with Costin but in the company of James Murray (Angus Macfadyen), a wealthy egoist whose obesity and general negativity deal an insurmountable blow to a trip in 1912, the year after Machu Picchu was discovered in the Andes.

Fawcett's pursuit of his obsession is then delayed by more than a decade, primarily by World War I. Although nearing 50, the colonel jumps into the fray, and Gray, working on limited means, delivers a devastating microcosm of the Battle of the Somme, one of history's bloodiest clashes, and one which leaves Fawcett temporarily blinded. Compressed, taut and devastating, it's an outstanding action sequence, one that pointedly conveys the essence of that wasteful war in miniature.

While admitting that, “I'm an old bastard now,” Fawcett by the early 1920s is so convinced of the existence of “Z” (and is now so steeped in mysticism) that he plots a third expedition with his 20-year-old son Jack (Tom Holland) as his companion. Gray shifts into advanced lyrical mode in this climactic stretch, as Fawcett proceeds, as if drawn by a sense of personal destiny, into an area he's warned is populated by hostile warring tribes. “A man's reach should exceed his grasp,” Fawcett philosophically intones as he, Jack and their small party press ahead toward their fate, which remains uncertain to this day.

One welcome difference between The Lost City of Z and most films devoted to male adventure is that, here, the “downtime” spent with wife and family is alive and laced with potent push-and-pull. Gray clearly takes the conflict between domesticity and the call of the wild seriously and he's greatly helped by Miller, who really brings Nina Fawcett alive in a layered performance despite limited screen time. Also welcome is the lingering doubt about Fawcett's wisdom in bringing his untested son along on the final expedition, no matter the youngster's naive personal enthusiasm.

Executive producer Brad Pitt and then Benedict Cumberbatch were both set at various points to play Fawcett, either of whom would have tilted the film more toward being a star vehicle (and would no doubt have occasioned a bigger budget as well). This won't be the film that makes Hunnam a star, but, after not exactly popping in the likes of Pacific Rim and Crimson Peak, his fine, robust work here will be taken seriously. The performance ripens and matures as the character does; you take the man's fitness and stamina for granted, along with the ambition, but the handsome blond actor also effectively registers the character's evolving strategies of dealing with upper-class snobbery and authority, as well as his own growing sense of purpose and destiny. In the end, even if Fawcett may not rank in the upper echelon of enigmatic British explorer-heroes such as James Cook, Charles “Chinese” Gordon, Ernest Shackleton and T.E. Lawrence, you sense he's indisputably related.

Exquisitely shot (on celluloid) by Darius Khondji in Northern Ireland and the Colombian jungle, the film exceeds its limited means in every respect. Exemplifying its traditional aesthetic virtues is Christopher Spelman's score, which, in its vigor, beauty and unfailing efforts to amplify the narrative action, evokes past masters from Max Steiner to Miklos Rozsa.

Venue: New York Film Festival (closing night)
Opens: Spring 2017 (Amazon Studios)
Production companies: Bleecker Street, Plan B, Sierra Pictures, Keep Your Head, MadRiver Pictures
Cast: Charlie Hunnam, Robert Pattinson, Sienna Miller, Tom Holland, Angus Macfadyen, Edward Ashley, Clive Francis, Ian McDiarmid, Franco Nero, Matthew Sunderland, Johann Myers, Daniel Huttlestone, Harry Melling
Director-screenwriter: James Gray, based on the book by David Grann
Producers: Dede Gardner, Jeremy Kleiner, Anthony Katagas, James Gray, Dale Armin Johnson
Executive producers: Brad Pitt, Marc Butan, Mark Huffam, Felipe Aljure
Director of photography: Darius Khondji
Production designer: Jean-Vincent Puzos
Costume designer: Sonia Grande
Editors: John Axelrad, Lee Haugen
Music: Christopher Spelman
Casting: Kate Ringsell

Not rated, 142 minutes