For fans of Leonardo DiCaprio, one of the constant criticisms we face is that the boyish 41-year-old, five-time Oscar-nominee doesn’t have the gravitas or heft necessary to play dark, complicated adult characters. Detractors can’t get past his movie-star looks, permanently seeing him as the youthful scamp Jack Dawson from Titanic. What these critics don’t grasp is that this boyishness has always been part of DiCaprio’s appeal: In films ranging from the domestic tragedy of Revolutionary Road, to the thinking-man’s action of Inception, to the psychological horror of Shutter Island, DiCaprio has played characters whose handsome, composed surface is undercut by insecurity and grief. His protagonists are half-formed men trying to convince themselves and the world that they’re not about to implode.

With The Revenant, even that argument may no longer be necessary to silence his naysayers. The survival film from Birdman filmmaker Alejandro G. Iñárritu may not contain DiCaprio’s greatest performance, but it certainly features his most thoroughly profound grownup role. The baby face is buried behind a thick beard but, more importantly, it’s been replaced by a gripping, primal urgency that he’s never displayed before. In the past, his best characters juxtaposed poise and panic. In The Revenant, DiCaprio taps into something untamed within himself.

The movie stars DiCaprio as Glass, a scout guiding a hunting expedition across the American frontier in the 1820s. Mourning the death of his Pawnee wife and keeping a close watch on his teen son Hawk (Forrest Goodluck), Glass works alongside a motley crew of fur trappers, including an ornery coot known as Fitzgerald (Tom Hardy), as they brave attacks by Native Americans to collect animal pelts that will fetch top dollar. But after Glass is nearly killed by a bear, the team’s thoughtful captain (Domhnall Gleeson) realizes that they must leave him behind, tasking Fitzgerald, Hawk and an impressionable younger trapper named Jim Bridger (Will Poulter) to ensure that Glass has a proper funeral. Instead, the callous Fitzgerald kills Hawk while Jim isn’t looking and leaves the weak, uncommunicative Glass to die in a shoddy grave.

Glass’s anger at watching Fitzgerald murder his child—and his commitment to delivering vengeance—drives everything that follows, as the grievously-wounded scout journeys back to the trading company’s outpost. This is a performance in which moans, screams, grunts and anguished cries outnumber words: Glass can barely speak after the bear nearly rips out his throat, and since he spends most of The Revenant alone, he doesn’t have anyone to talk to, anyway.

Consequently, this is DiCaprio’s rawest performance, in keeping with a character attuned to the looming, imposing trees and unforgiving, inhospitable Rocky Mountain terrain. Glass feels like a force of nature, although DiCaprio emphasizes the character’s humanness, never letting us forget the endurance test Glass must complete to find Fitzgerald. 

At the same time, Glass is just one component in The Revenant’s sweeping scope. Iñárritu has envisioned a grand survival story with almost operatic stakes. A booming, minimalist score from composers Ryuichi Sakamoto and Alva Noto (featuring additional music from Bryce Dessner of the indie-rock group the National) drapes the proceedings in an ominous, existential elegance. Cinematographer Emmanuel Lubezki’s floating, hovering cameras—reminiscent of his recent work with director Terrence Malick—help give The Revenant an almost ethereal quality, elevating its hero’s journey to the level of myth while making the 19th-century settings seem like they originate from another planet.

Iñárritu has long made films in which the miserable plights of ordinary souls form the foundation of searing drama. (He’s been our self-proclaimed master of martyrdom, successfully in 21 Grams, less so in Babel and Biutiful.) Ironically, the filmmaker’s slight deviation from that self-serious strategy, finding the dark humor in Birdman’s flailing thespian, netted him three Oscars, but with The Revenant he returns to his celebration of noble suffering. Where some of his previous efforts drowned in their own sanctimonious sympathy for luckless Jobs, The Revenant’s masterful construction is so engrossing, its unblinking portrait of the barbarity and splendor of the unspoiled American frontier so complete, that Iñárritu’s obsessions for once seem elemental rather than contrived, an organic extension of the unforgiving odyssey undertaken by Glass.

On his journey, Glass encounters fearsome local tribes, an unscrupulous French expedition, and a brutal winter. And along the way, Iñárritu shows off an underappreciated aspect of his filmmaking—lethally efficient action sequences. In his debut Amores Perros and briefly in Biutiful, he’s had opportunities for tightly woven set pieces, but The Revenant boasts some exceptional scenes, beginning with a Native American ambush at the outset, continuing with a horrifying bear attack, concluding with Glass and Fitzgerald’s final stand. 

Tom Hardy’s character proves to be a loathsome foe for Glass; the actor exudes contemptible savagery as a man who’s as wild and violent as the world around him. Hardy has always come across as a brawler on screen—grim stare and hulking physique—but DiCaprio matches him glare for glare and grunt for grunt. Iñárritu aims for the poetic and the mystical in The Revenant, but his leading man crawls through the dirt on the way to his character’s gruesome reckoning. Oscar observers are talking about DiCaprio being “due” to finally win an Academy Award. His performance transcends such measly considerations—it’s etched in stone, forged in blood, towering as a totem. 

Grade: A-

Grierson & Leitch write about the movies regularly for the New Republic. Follow them on Twitter @griersonleitch or visit their site Listen to their film podcast below.