In April of 1992, 24-year old Christopher McCandless ventured into the Alaskan wilderness with a rifle, a sleeping bag, 10 pounds of rice and maybe 10 more pounds of books. He never returned. McCandless had already spent two years hitching around the United States, earning pocket change at odd jobs here and there, spending what he needed to and burying or burning the rest. Having too much money made tramping too easy, McCandless thought. If it was a tough life, well, that was the point.

Whatever else he might have thought of Into the Wild, McCandless would surely have appreciated the difficult road screenwriter/director Sean Penn traveled to adapt author Jon Krakauer's account of McCandless' adventure; simply acquiring the rights to the source book was a decade-long process. Penn's passion for the material shines through in the finished product, a beautifully moving film about a happy story with a tragic ending.

McCandless (played impressively by underrated young actor Emile Hirsch, last seen in Alpha Dog) wasn't some kook -- a graduate of Emory University, he was perhaps too smart for his own good. A well-read disciple of Tolstoy and London, McCandless determined that he had to escape from our "sick society." And so he chopped up his credit cards, donated his savings to Oxfam, and took to the road.

Penn never fully explains how our heroic hobo, who grew up in a life of comfort and privilege in Virginia (with parents played by William Hurt and Marcia Gay Harden, whose lips remain so harshly pursed they could cut glass), developed what his sister Carine (Jena Malone) describes as his "fiercely rigorous moral code." Perhaps to Penn, who is clearly empathetic to McCandless' dreams, if not his ultimate actions, no explanation is needed. Instead, he cuts between two different stories: McCandless' increasingly desperate struggle for survival in Alaska, which he saw as the "the final and greatest adventure," and his previous two years hoofing it around the country on his "spiritual pilgrimage." Penn interweaves the threads with an eye toward revelation and occasional irony, so that McCandless' most ecstatic moment of spiritual understanding (in a chapter entitled "The Getting of Wisdom") leads directly into his most desperate search for food near the end of his life.

McCandless was obsessed with dropping out of society, eventually going to Alaska to start his own little community of one; he met remarkable people and started wonderful relationships, only to surrendered them to his own unconquerable restlessness. Well before McCandless confesses to his journal that happiness is "only real when shared," Penn has made us acutely aware that the idealized world ( if not solitude) McCandless searched for probably existed amongst the strangers with whom he forged friendships, like fellow tramps Jan (Catherine Keener) and Rainey (Brian Dierker), who take Chris in as pseudo-adoptive parents, a mischievous grain harvester named Wayne (Vince Vaughn) and soulful widower Ron Franz (an award-worthy Hal Holbrook).

There are a few too many overly sincere attempts at profundity (the movie opens with a Lord Byron quote), but Penn's insight into his subject's core desire -- his need for "ultimate freedom" and a desire "to kill the false being within" -- propels the film past its flaws. We share McCandless' successes and failures and come to care greatly about his survival even if he we can't fully relate to his motivations. In his youth, Penn probably would have loved to play Hirsch's part -- it's meaty (as well as meatless: Hirsch had to drop plenty of weight to approximate death by starvation). But in directing the film he adopts the stance an older brother might have taken in the face of Chris's iconoclastic behavior: understanding tempered with grief.

Penn admires his protagonist’s recklessness even as he grieves over its end result, and brings dignity and compassion to his on-screen death. In describing the glory of the tramp life to a friend, McCandless once wrote "the simply beauty was too good to pass up." The same goes for Penn's film.