If you haven't read the original book, on the page Cloud Atlas unfolds like a piece of music, with six stories playing alongside each other, building to a crescendo and then unwinding to a lingering final note. Just to make it more complicated, each of these stories takes place in a different era and represents a different form of storytelling. Kicking off with the diary entries of a notary aboard a tall ship that's traversing the Pacific Ocean in 1849, Mitchell then moves on to the private letters written by a vagabond musician working with a tyrannical composer in '30s-era Belgium, followed by a pulpy '70s mystery novel about a journalist investigating a shenanigans at a nuclear power plant, a contemporary farce starring an elderly publisher who is committed to a retirement home against his will, the interrogation of a soon-to-be-martyred clone in 22nd century Seoul and, finally, a Hawaiian goat-herder's first-person account of an adventure he experienced in a distant, post-apocalyptic future. Although certain character and elements recur from story to story, they aren't linked together by an overarching plot as much as an overarching theme, the idea that one act of bravery can challenge and potentially upend the systemic injustice that seems to plague civilization throughout history.

That theme -- not to mention all of these storylines -- is preserved in the movie, but it takes a backseat to the filmmakers' main interest, which is exploring the way individuals can change (or not change) through time. Where Mitchell hinted at the notion of reincarnation, Twyker and the Wachowskis make it explicit, casting the same group of actors in each of the six storylines, frequently in roles that suggest some kind of karmic progression, regression or status quo. Tom Hanks, for example, starts out as a villainous doctor poisoning the unwitting hero (Jim Sturgess) of the 19th century section and eventually evolves into heroic goat-herder in the post-apocalyptic story thread. On the other hand, James D'Arcy begins as the devoted lover of the musician (Ben Wishaw) who occupies the center of the '30s segment, only to end up as the stern interrogator of the clone in future Seoul. And then there's Wachowski stalwart Hugo Weaving, who pops up in each narrative as the ultimate incarnation of evil, whether that's as a sadistic Nurse Ratched-style medical caretaker (in full drag, no less) or the literal devil. Not all of the actors get such clear arcs though, either due to their own limitations or the limitations of the different storylines; Halle Berry, for example, shows up in various guises (most notably the '70s journalist), but always has the same bland personality, while Jim Broadbent (the movie's MVP) does a brilliant job creating distinct characters in each timeline, but they don't readily map onto the conceit of karmic progression that the filmmakers have built into the movie. (It must be said that although the extreme, make-up enhanced makeovers of the various cast members is impressive, they can also somewhat distracting. It's all too easy for the viewing experience to became an extended "Where's Tom and Halle?" guessing game.)

Being the sentimentalists that they are, the Wachowskis (and to a lesser extent Tykwer) also make love a defining force in the film, with couples losing and then finding each other again through the ages. Thus, Sturgess and Korean actress Doona Bae play lovers in both 1849, when they're husband and wife, and 22nd century South Korea, when she's the clone-turned-martyr and he's the rebel soldier who frees her from captivity and enlists her in a doomed uprising. Meanwhile, after feeling the first stirrings of romance for Berry's intrepid journalist upon meeting her in the '70s, Hanks has the opportunity to get close to her two millennia later, when she arrives in Hawaii on a mission to contact whatever remnants of mankind that might still be out there living amongst the stars. Mitchell avoided this kind of grandly romantic gesture in the book, which took a considerably darker view of the affairs of the heart. Considering the grand sweep of the movie, it's no surprise that the filmmakers felt that an injection of grand romance would be appropriate; unfortunately, these grafted-on love stories often feel more cloyingly sentimental than swooningly sweet. To be fair though, it's commendable that there's not a whiff of commercial calculation in the movie's heightened emotional state. These directors are never anything less than earnest and put their whole hearts into their films, even when it invites ridicule (as in those marvelous, severely underrated Matrix sequels and Tykwer's sorely neglected, wonderfully insane Perfume). I may not buy into their notion of a love that can transcend time, but I can absolutely believe that they believe in it 100 percent.

But the film's most radical departure from the novel by far has to be its structure; where Mitchell presented the stories as standalone pieces, the Wachowskis and Tykwer intercut between each timeline, driving home the idea that they are telling one story that happens to be made up of six parts, as opposed to six stories based around one uniting theme. This is the key alteration that fans of the book might have the hardest time accepting and I'll freely admit that I'm still uncertain where I stand, especially after only a single viewing. On the one hand, I sorely miss the rich sense of detail, not to mention the virtuoso variation in style, that's present on every page of Mitchell's book. By going all-in on the idea that -- as the tagline says -- "Everything is connected," the filmmakers sacrifice the unique identity of each story. Mitchell's deft intermingling of genres is completely out the window; the production design and costumes may change to reflect the different eras, but the movie establishes a single house style and sticks to it over the course of its three-hour runtime. (Again, I understand the filmmakers' reasoning, but the lack of variation threatens to become grinding and monotonous.) Worse still, so much detail has been lost due to time constraints and the "one world, one story" approach that I'm not sure all of the individual stories even make sense as stories anymore. Having read the book, I was able to fill in the gaps, but I have no idea whether a viewer coming into this movie cold will entirely understand why, for example, this particular clone is so vital to the 22nd century rebellion or what specific mystery the '70s journalist is trying to crack about the nuclear power plant. (Then again, those unfamiliar with the book won't be aware of what's missing anyway and may find the general gist of the stories perfectly understandable.)

Even as I was all too aware of what was lost in Cloud Atlas's transfer to the big screen, as someone who prefers fully-realized, if flawed interpretations of great books to stridently faithful books-on-film, (for example, if given the choice between Spike Jonze's Where the Wild Things Are and Gary Ross's The Hunger Games, I'd go with Spike every time) I can't help but be impressed by the enormous amount of technique and thought that the directors brought to the movie. Rather than just parroting back Mitchell's words, the Wachowskis and Tykwer have given us a version of Cloud Atlas that reveals what the book means to them. And while my reading of the text differs from theirs in some areas, they've put forward an impassioned argument for their point of view. Beyond that, the movie works quite well as a piece of big-budget spectacle; the different time periods are beautifully rendered -- for the record, Tykwer was responsible for the '30s, '70s and present day sequences, while the Wachowskis tackled the 19th century and both of the distant futures -- and make expert use of both practical and digital effects. (I was particularly taken with the 22nd century scenes; few directors in movies right now are creating futurescapes as grandly immersive as the Wachowskis.) It's entirely possible that a second viewing of Cloud Atlas will sweep away any reservations I have about the way the filmmakers have adapted the book. Or perhaps it'll make me even more critical of some of their choices. Either way, I know that this is one adaptation that I'll happily watch multiple times precisely because it offers an experience I couldn't get just reading the book.

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