"The Lost City of Z" is the adventure film to see this year.

The Lost City of Z, directed by James Gray, depicts the life of the English adventurer Percy Fawcett (played by Charlie Hunnam). In the early 1900s, Fawcett embarked on several expeditions to South America in search of an alleged Amazonian civilization which he called “Zed.” The Lost City of Z, which is a classic adventure tale punctuated with humanism, is a meditation on exploration, masculinity, empire, and, ultimately, humanity. The film juxtaposes the supposed savagery of ancient tribes of Amazonian people with the supposed civilization of the Victorian English, and shots of their starched suits and tea services and their stuffy meetings in stuffy rooms frequently fade into vistas of humid jungles and the winding Amazon, where Fawcett and his team of fellow adventurers (including Costin, his right-hand man, who’s played by Robert Pattinson, concealed beneath a great bird’s nest of a beard) encounter people who’ve seldom, if ever, observed white flesh before.

Gray paints a vivid picture of the post-Victorian English world and all its political and social problems, without succumbing to preachiness. Or, perhaps it is a new kind of preachiness, one that feels more palatable than direct soapboxing. When Fawcett’s wife Nina (Sienna Miller, giving a fine, tough performance) asks to come along with Percy on his second voyage, he lectures her on a woman’s role in the family (in this case, to stay behind and pick up the pieces if he never comes back) and on women’s inherent physical inferiority, unconvinced by his wife even after she’s born him three children. Nina relents. Gray isn’t telling us what to think, but he’s conscious of the wrong-headed thinking of the period.

And the allure of male power and the lies of empire remain a dominant force in the world even today. But part of Gray’s talent as an artist is his ability to depict humans in all their complexity. On the third, fateful voyage, Percy’s now-grown son Jack accompanies him, and when they realize they may never return to England, a kind of mystical peace sweeps over Percy as he reflects on the deeper implications of their journey: they’ve left all the silly, superficial machinations of society behind and have discovered something primally beautiful and true: the inherent mystery of life, and the immutability of destiny.

Gray has a healthy love for the adventure genre, and he provides the usual touches we’ve come to expect from these movies (going all the way back to Haggard’s King Solomon’s Mines): the bugs, the storms, the snakes, the raging river, as men seemingly travel back in time to confront some kind of mystical destiny. In one scene, the men are forced to jump out of their raft to avoid the sharp arrows being fired at them by natives, only to be accosted by a school of piranha. As I think back upon this scene, what strikes me most is Gray’s elegance even in the midst of something as frightening as this moment. Those arrows swoop down like little rockets: he shows us just how terrifying it would be to face a shower of pointy spears coming down on you; and yet, Gray resists the urge to sensationalize this moment. (In my mind, I couldn’t help thinking of that 1978 horror movie, Piranha, which probably added to the tension.)

The intensity lasts but a minute, and then they’re back on the raft, back on their long, long journey into the unknown. These moments of sensationalized terror, which would be the high points of an Indiana Jones movie, are not the focal point of Z. The thrill of discovery drives Fawcett on, despite the man-eating fish and the spear-throwing natives and the bugs and the starvation.

But within that act of discovery is the deeper realization that, as Fawcett says in the movie, the world is unknown to us; there is so little that we really know, so much left undiscovered. The obsessive need to understand everything is probably folly, and probably arrogance, as Gray’s film shows us often: Fawcett himself is a man dogged by feelings of inadequacy (his father was a notorious drunkard that left a blight on the family name); we see him in the beginning of the film rounding up a bunch of Irish soldiers as they hunt for a sleek, impressive buck in the woods; It’s Fawcett’s gun that kills the animal dead, but at the party of Irish and English military personnel, Fawcett’s excluded from the honorary table with the big dogs, because he’s from a bad family.

It’s English class snobbery which initially compels Fawcett into the South American jungle, even though his smart, independent, and loving wife Nina knows she may never see him again. Each time he comes back to England is like a dream: another child has been more, each of them discovering their father like some phantom, whom they’ve only heard about. When Jack, the eldest boy, by now an adolescent, who’s watched his father go off on multiple failed missions to the Amazon, jeers, “You’re a failure!” and Percy strikes him, we’re stunned, but not surprised. Empire is nothing but the perpetuation of fatherly dominion taken to the macro level, and we can imagine a million English fathers experiencing similar feelings of dissatisfaction and failure in turn-of-the-century England.

The Lost City of Z recalls Martin Scorsese’s difficult but unforgettable film, Silence, the story of two 17th-century Jesuit priests searching for their mentor, a priest who left for Japan (where Christians are being killed for refusing to denounce their faith) and has never come back. These young priests confront their own doubts as they search for the man who gave their faith its meaning. Both of these films examine the dangerousness of inquiry: When Percy Fawcett argues for the existence of an ancient civilization in South America, he rattles the calcified hearts and minds of the old fogies at the Royal Geographic Society, threatening British religion with British rationality.

The Lost City of Z ponders these questions with poetic grace. Gray isn’t dogmatic or pedantic: he cares deeply for these characters, as he cared for Marion Cotillard’s prostitute in The Immigrant, a woman who went to confession and wondered if God could ever forgive her for the things she had done to help get her sister out of Ellis Island. Z goes one step further, in a sense, by wondering if we can dismantle our own beliefs and still look around us with a sense of dazzled wonder at the world, even though our own smallness becomes increasingly obvious. In James Gray’s films, the answer is yes. Or as Nina Fawcett puts it, “a man’s reach should exceed his grasp.”

Co-starring Tom Holland as the grown-up Jack Fawcett; Angus Macfayden as a wealthy British explorer who betrays Fawcett and his men; Edward Ashley, Ian McDiarmid, Franco Nero, and Harry Melling.