In the early 20th Century, Percy Fawcett travelled deep into the Amazon jungle on a quest to find a rumoured city of gold and maize. Seeing this life-long obsession play out would be reason enough to watch writer-director James Gray’s dynamic The Lost City of Z. But the film sets itself apart from the average adventure saga by assuming a pointed cultural perspective.

Gray places Fawcett in the context of the British age of exploration and empire, complete with assumptions about the so-called ‘primitive’ people of the Amazon and a huge dose of snobbery at home. Early in the film, Fawcett, an army major, is denied a dinner invitation because, as one member of the upper echelon says, “He has been rather unfortunate in his choice of ancestors.”

Lost City entrances and allures rather than grabs you by the throat

Sneering at such imperious assumptions is easy today. The mastery of Gray’s film, and of Charlie Hunnam’s subtle yet magnetic performance as Fawcett, is that they immerse viewers in the past, allowing the audience to appreciate the most radical aspect of Fawcett’s real-life journey: he goes from being a victim of his era to a man at its cultural forefront.

The film begins by displaying the elaborate trappings of the society that does not quite accept Fawcett. There is an action-packed fox hunt and a grand ball, and in between a lovely, intimate conversation between Fawcett and his wife, Nina (in an elegant and natural performance by Sienna Miller). He nicknames her Cheeky, and confides to her his sense of fleeting years and of failure.

Those early scenes establish both his character and the film’s deliberate pace. Even in the most dramatic jungle moments, Lost City works by entrancing and alluring viewers rather than grabbing them by the throat. Anyone who found Gray’s previous film, The Immigrant, too slow may feel the same about Lost City, but those who settle into its rhythm will be rewarded with a rich exploration into the mind of an Edwardian adventurer.

This is not the tale of two heartthrobs in the jungle; Hunnam handles that on his own

When the Royal Geographical Society asks Fawcett to go to Bolivia to chart the border with Brazil, he takes on the dangerous assignment because it offers a chance to redeem the family name that his alcoholic gambler of a father had sullied. He leaves behind the pregnant Nina, who understands that the sacrifice will be for the family’s long-term good.

Voyage of discovery

For that first expedition in 1906, Robert Pattinson arrives as Fawcett’s taciturn, loyal aide-de-camp, Henry Costin. Pattinson looks shabby, with a scraggly beard and wire-rimmed glasses. (This is not the tale of two heartthrobs in the jungle; Hunnam handles that on his own.) His character is flat, but he is part of the grand action the men face as an indigenous South American guides them in canoes and on rafts toward the source of the Rio Verde. They brave the blistering sun, and dodge arrows shot from riverbanks. In one act of desperation and wit, Fawcett disarms attacking Indians by having his British colleagues join him in singing Soldiers of the Queen. He also hears of the lost city, and finds shards of ancient pottery that suggest an advanced civilization.

Fawcett may be obsessed with the city he calls Zed, but he does not turn into a lunatic or megalomaniac, as more familiar movie explorers have (think of Kurtz in Apocalypse Now or the title character in Aguirre the Wrath of God). Even in the Amazon, Fawcett is constantly missing his wife and children. And when he gives a speech to the Royal Geographical Society on his return, holding up his shard of pottery, the scene reveals how dramatically his mind has been opened. He is jeered when he suggests that a South American civilisation might pre-date Britain’s, and accuses his dismissive colleagues of being “steeped in the bigotry of the church."

This is no jewel-coloured fantasy

He and Costin take up the quest again, in a trip cut short by a greedy amateur who tags along. They return just in time for World War One. Fawcett, by then nearing middle age, fights heroically at the Somme. Gray handles the battle scenes, and all his big set pieces, with calm expertise. His earlier works, including We Own the Night and The Yards, were gritty contemporary gangster movies. Lost City continues the epic historical ambition of The Immigrant, in which Marion Cotillard played a Polish woman forced into prostitution in early 20th Century New York.

Inward journey

Along with cinematographer Darius Khondji, Gray creates a subdued look for Lost City. Each scene is gracefully composed, yet a brown haze covers the scenes set in Europe, and the green of the jungle is toned-down. This is no jewel-coloured fantasy. The Bolivian scenes, shot in Colombia, are created with such immediacy that viewers may feel the urge to swat insects away.

At times Gray shoots Hunnam in glamorous, shadowy, matinee-idol profile. But Hunnam, best known as a biker in the series Sons of Anarchy, proves himself an actor of genuine depth. He captures Fawcett’s many emotional layers, as he grapples with the competing forces of ambition and responsibility.

In 1925, Fawcett’s oldest son, Jack (Tom Holland, playing with a mix of determination and innocence) joins him in one more search for Z. By then they have competition. “The Americans will venture there with their guns, and then we must pray they do not destroy the Indians,” Jack tells his father. Such lines, like some of Nina’s proto-feminist remarks, are a bit too blunt to work as dialogue, but they are scarce.

In real life, Fawcett and Jack disappeared during their trip, their fates never determined. David Grann’s best-selling book, on which the movie is based, posits a likely solution to the mysteries of the disappearance and of Z. Gray’s ending is more ambiguous and the film’s stunning final shot is beautifully imagined.

Gray’s own imaginative journey into Fawcett’s character shapes this quietly eloquent film. Although Fawcett was forward-thinking about the Indians, to the end he retained the certainty and righteousness of the Kipling-reading man who had set off on an adventure decades before. “Be brave,” he tells his son when they are surrounded by members of a hostile tribe. “Nothing will happen to us that is not our destiny.” 


If you would like to comment on this story or anything else you have seen on BBC Culture, head over to our Facebook page or message us on Twitter.

And if you liked this story, sign up for the weekly features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital and Travel, delivered to your inbox every Friday.