In 1820s America, frontiersman and fur trapper Hugh Glass (Leonardo DiCaprio) joins a pelt-gathering expedition under the direction of Captain Andrew Henry (Domhnall Gleeson) in the unsettled wilderness of what are today the Dakotas. The large hunting party, which also includes Glass' half-Native American teenage son Hawk (Forrest Goodluck), disgruntled roughneck John Fitzgerald (Tom Hardy), and the young and inexperienced Jim Bridger (Will Poulter), are soon attacked by the Arikara Indians. The natives are searching for a female member of their tribe who was kidnapped and abused by a band of hunters, and they kill most of Captain Henry's outfit. Glass, the most experienced woodsman of the remaining trappers, charts a new course inland to a U.S. fort to avoid further confrontation with the natives -- much to the consternation of Fitzgerald, who's more concerned about getting paid for this job. As conditions worsen and food becomes scarce, distrust runs high amongst the group. While hunting alone for sustenance, Glass encounters a mother grizzly bear and her two cubs. The bear defends her clan by ferociously mauling Glass, leaving him with life-threatening wounds and a broken leg. Fitzgerald, Bridger, and Hawk are supposed to stay behind to monitor Glass and give him a proper burial after he dies. Anxious to receive his money and avoid the Arikara, Fitzgerald instead murders Hawk in front of his father and leaves Glass to die, unarmed and without any supplies, in a shallow grave. But Glass survives and seeks revenge against Fitzgerald, pursuing him across the massive, unforgiving land. The Revenant is immersive, event cinema at its absolute finest. Director Alejandro González Iñárritu and co-writer Mark L. Smith turn a straightforward, revenge-minded Western into a study of the natural world, mortality, and the human condition. Glass is haunted by visions of his late wife, a Native American woman, and is confronted with the crippling emotional toll of Hawk's murder during his incredible journey of vengeance. Improbable as it may seem, Hugh Glass really did exist, and The Revenant was adapted from Michael Punke's 2002 nonfiction novel based on the larger-than-life man. The opening attack by the Arikara on Glass and the trappers is directed with such chaotic fervor that it calls to mind Saving Private Ryan. Iñárritu demonstrated his skillful sense of pacing with 2014's Best Picture winner Birdman, and he again relies on cinematographer Emmanuel Lubezki to pull off breathtaking tracking shots. The Revenant bounces seamlessly between moments of extraordinary action and extended sequences of pure human suffering, betrayal, and survival. Not all moviegoers want to see these challenging cinematic exploits on display, but if they do appeal to your sensibilities, The Revenant is a masterpiece of filmmaking. Likewise, the photography here is a reminder that Lubezki operates in a class of his own. The crushing landscape of the frontier is painted in muted greens and greys, while the spatter of crimson blood on the snow-covered terrain serves as a stark reminder of the unforgiving nature of this environment. Shot using only natural light, Lubezki's upward-panning shots of the forestry above the characters are so artfully affecting that Terrence Malick would blush. Each snowstorm and river rapid that Glass encounters on his odyssey toward Fitzgerald is a visceral delight. So much of the press surrounding The Revenant has been focused on DiCaprio's chances at winning his first Academy Award. He's never been more committed to a role -- we see him bearded and bloodied, reserved and delirious -- and he delivers a stunning performance. Glass is pushed to the brink of physical and mental anguish, and DiCaprio makes us feel every shred of his pain. He's matched pace for pace by a fantastic Tom Hardy, as well as proficient work from Gleeson and Poulter. Iñárritu depicts this singular quest in painstaking, harrowing detail -- Glass is forced to survive by sucking the bone marrow from a skeleton and suturing his wounds with less-than-ideal resources. He's consumed with revenge, but the harsh reality of the frontier is that these pursuits eventually amount to very little. No character, tribe, or yearning is above falling into moral depravity, and the human truths that Iñárritu probes in The Revenant are as bleak as the plains themselves. Iñárritu asks a lot from audiences who are willing to endure the film's strife, but the payoff is a picture of both astonishing beauty and grueling agony.