Readers of David Mitchell's massive, ruminative, centuries-spanning 2004 opus claimed it was unfilmable, but they were wrong; the key is in adapting said literature into a filmic language without losing the ideas and spirit behind the written word. "Cloud Atlas" is a staggering, symphonic watermark in cinema, a 172-minute historic sci-fi travelogue of the past and distant future, of humanity living and dying and loving and fighting to change their own existences and those that will set foot on the same ground they've walked on long after they're gone. Written for the screen and directed by Tom Tykwer (2009's "The International") and Lana & Andy Wachowski (2008's "Speed Racer"), the film is easily the most accomplished work of all their careers, a sweeping study on how our actions, large and small, have the power to reverberate through the ages. Beyond that, its visuals are often awe-inspiring in their grandeur and artistry, with Frank Griebe's (2006's "Perfume: The Story of a Murderer") and John Toll's (2012's "The Odd Life of Timothy Green") electric cinematography fully living up to the immense scope that the story demands. Moving with urgency, Alexander Berner's (2011's "The Debt") editorial prowess masterfully finding the parallels between its six time frames, "Cloud Atlas" nonetheless takes the time to listen to, and exhibit aching empathy for, its mountainous collection of characters (nearly all of the actors are featured in up to six different roles, many of them unrecognizable under make-up and effects wizardry). The finished picture is a sensory overload in the best way, bursting with such imagination and thematic complexity that one viewing is simply not enough by a long shot.

The film opens with a breathless five-minute montage criss-crossing five hundred years and six separate eras—that's enough to overwhelm anyone—but stick with it. "There's a method to this madness," the voiceover assures us, and indeed there is, as each of the individual narratives come into focus, slowly revealing their connections to the greater whole. Stranded in the Pacific Islands in 1849, youthful notary Adam Ewing (Jim Sturgess) is welcomed aboard a ship with, among others, the deceptive Dr. Henry Goose (Tom Hanks) and, later, mistreated escaped slave Autua (David Gyasi). A copy of "The Pacific Journal of Adam Ewing," which he pens during the voyage, finds itself in the hands of Vivyan Ayrs (Jim Broadbent), a cranky veteran composer in 1936 Cambridge. Robert Frobisher (Ben Whishaw) has bid farewell to his lover, Rufus Sixsmith (James D'Arcy), to work as Vivyan's apprentice, the two of them collaborating on a classical piece called "The Cloud Atlas Sextet" before a disagreement leads to an irrevocable act of violence.

In 1973 San Francisco, journalist Luisa Rey (Halle Berry) happens upon the very rare sextet in a record shop and swears she's heard it before despite little logical way that she could have. Soon after a chance encounter with the elderly Sixsmith on an elevator during a power outage, he is found dead. Little by little, Luisa becomes embroiled in a conspiratorial investigation connecting Big Oil with nuclear power chief Lloyd Hooks (Hugh Grant). Inspired by this, the first so-called "Luisa Rey Mysteries" novel comes across the desk of aging, down-on-his-luck publisher Timothy Cavendish (Jim Broadbent) in 2012 London shortly before he's shipped off to a nursing home he desperately wants to escape from. In the futuristic metropolis of Neo Seoul, 2144, a genetically engineered fast-food worker named Sonmi-451 (Doona Bae) falls in love with star-crossed rebel Hae-Joo Chang (Jim Sturgess) just as she learns the unimaginably bitter truth of what really happens to her kind when they supposedly ascend to a higher plane. And on the Big Isle, "106 Winters After the Fall," psychologically tortured Polynesian tribesman Zachry (Tom Hanks) is visited by Meronym (Halle Berry), one of the last connections with a technology-based civilization. Together, they embark on a journey to a dwelling "above the sky, beyond the stars," where the truth about the now-revered Sonmi-451 resides.

"If God created the world, how are we to know what can be changed and what must stay the same?" one character asks early in "Cloud Atlas." In response, the film argues that quite a lot can be altered, human will and the minutiae of one's actions—not to mention all of the bigger things one must take a stand for and against—enough to change the course of history. Thus, Adam's experiences sailing across the Pacific in the 1840s, on a ship he was not originally supposed to be on, is enough to shed light on the period's wrongheaded racism and his path toward abolitionism in the face of familial and societal pressure. In the 1930s, the relationship between Frobisher and Sixsmith is set on a doomed course the moment the former leaves home for professional pursuits, complimented in the tragic 22nd-century tale of Sonmi-451 and Hae-Joo Chang, soul mates whose time together is over before it begins. The same might be said of Luisa Rey and nuclear power plant worker Isaac Sachs (Tom Hanks), the two of them making an undeniable connection that devastatingly will never be substantiated. As for Zachry and Meronym, enlightenment into truths of the universe come with a great hardship, but also newfound hope. Writer-directors Tom Tykwer and Lana & Andy Wachowski, concurrently lensing with two different film crews—the picture was shot across Spain, England and Germany—do not pretend they know all the mysteries of life and death, but they do suggest that love is strong enough to outlast the end of one's earthly consciousness. Meanwhile, what we do in the here and now very likely will echo through time in ways we have no way of knowing.

Tom Hanks (2011's "Larry Crowne") and Halle Berry (2011's "New Year's Eve") lead an astonishing ensemble, all of them at one time or another disappearing into characters of different genders and ethnicities. Sometimes the actors can be pinpointed, while at other times they can't, even though the viewer subconsciously recognizes they look familiar—all of this just another layer to a film that hints without spelling out the notion of reincarnation and souls existing beyond physical bodies. Portraying so many different personages gives the actors a freedom they don't normally have, and all of them are clearly thriving with such wide parameters in which to play. In her biggest part of the six, Berry is front and center as Luisa Rey, an intrepid journalist in the 1970s who gets caught up in her own paranoid thriller complete with shady guys in dark cars, an untouchable man of power, and a secret that could spell near-cataclysmic trouble. In this story, she senses something between herself and Hanks' Isaac when she journeys to the nuclear reactor plant on Swanneke Island, just as there is a chemistry between Berry's Meronym and Hanks' Zachry, the latter haunted by malevolent visions of the Devil himself, Old Georgie (Hugo Weaving). When Old Georgie comes calling, in one scene appearing to him on the side of a perilous cliff, urging him to let go of the rope holding Meronym as she dangles thousands of feet in the air, it's disconcerting bordering on nightmare-inducing. Once at their destination, the outcome of Sonmi-451's metamorphosis from enslaved fabricant to brave revolutionary is revealed.

In just one of her multiple parts, Doona Bae (2007's "The Host") is deeply touching as Sonmi-451, the sheltered vision of what she thought about the world nothing but a smokescreen. Jim Sturgess (2011's "One Day") stars as Adam Ewing, carrying a box of gold coins that just might get the better of a ruled-by-greed Dr. Henry Goose, as well as the heroic—and Asian—Hae-Joo Chang, taking a chance on his belief in, and feelings for, Sonmi-451. Jim Broadbent (2011's "The Iron Lady") is a joy as Timothy Cavendish, never forgetting the woman he loved all those years ago and now faced with a bleak finality as he gets left at a nursing home lorded over by brutish Nurse Noakes (Hugo Weaving). Speaking of Hugo Weaving (2011's "Captain America: The First Avenger"), as memorable as his Nurse Ratched is, he's even more unforgettable as Old Georgie, a demonic voice in Zachry's head that materializes like someone's worst imaginings mingled with memories of Zelda from 1989's "Pet Sematary." Keith David (2012's "Smiley") is one of those hard-working veteran actors difficult to resist in any movie, and he's most prominently here as Luisa Rey's confidante Joe Napier, getting in on the chase when the two of them are ruthlessly hunted down on the city streets of San Francisco.

The butterfly effect is in full motion throughout "Cloud Atlas," hidden in the very fabric of its rich storytelling and the boundless levels one cannot wait to explore again even while the film is still playing out. A tapestry of juggled genres and two savvy "Soylent Green" references woven seamlessly together, they all add up to an entertainment that is, at once, a stirring high-seas adventure; an engrossing period drama that is everything 2011's confused folly "Anonymous" yearned to be; a conspiracy-based potboiler favoring suspense and the intimacy of its characterizations over cheap plot gimmicks; a bitterly sweet comedy of manners and quick getaways; a dystopian science-fiction saga with vivid sights, dizzying action, and sobering twists of an outright horrific nature, and a post-apocalyptic allegory that encapsulates many of the earlier ideas while providing a conclusion that somehow seems to arrive full-circle despite being set half a millennia from where it began. With a scattered collection of years ticking away at a propulsive rate, the sublime music score by Tom Tykwer and Reinhold Heil & Johnny Klimek (2008's "One Missed Call") becoming one with its whirlwind of imagery, the film's nearly three-hour running time rushes by in a blink, emulating the passage of Old Father Time. "Yesterday, my life was headed in one direction, and today, it's headed in another," writes Isaac Sachs as he sits on an airplane, unaware that it's about to take a sharp unforeseen third turn within seconds. If life is made up of a series of choices leading us toward fates we have no way of guessing, then how much control do we have in our fight for personal freedom? It's a question to which there can be no finite answer, and yet we go on. We must. Dripping with startling ambition, divine beauty and purpose, "Cloud Atlas" is a transcendent motion picture, unlike any other that's ever been made. Mere descriptions cannot possibly do it justice.