Few things are sadder than watching a good story being axed by shoddy execution. There are basically a million ways that director Yukihiko Tsutsumi could have taken his live-action adaptation of Naoki Urasawa's 20th Century Boys. Balls-to-the-wall action, knowing camp, creepy pulp mythology—the story has the potential to be any of them. Potential that Tsutsumi roundly squanders, turning out, rather than a film, a chain of filmed events, an exercise in base narrative that drains the life from a lot of fine scenes before hanging them in a line like butchered beeves in a warehouse.

Among the butchered are a disconcerting confession by a gut-shot cultist in a bum's hut, a surreal confrontation with a masked madman at a glam concert, a kidnapping and human immolation by a surging crowd at a convenience store, and...well, the list goes on. Every one is wound up, waiting to blossom into something eerie and immersive, and every one dies right there on the vine. The method of their deaths varies: poor cinematography makes the glam concert look like bad '70s porn (minus the porn), off-kilter acting sabotages the confession, and a general inability to stage, frame or choreograph action leeches the kidnapping's power. But dead they are, regardless of methodology, and a great many more besides are killed by combinations thereof.

The movie takes this collection of junked scenes and simply strings them together, with no concern for how one segues into the next or how they might be arranged to create tension, excitement, or even build to a climax. Partly that is the fault of the film's serial origins. The movie is filled with chapter stops and narrative leaps that make sense in a weekly publication, but that chop the hell out of a feature film. The film does move forward, but clumsily and in fits and starts—sort of the narrative equivalent of bad stop-motion. It takes its frankly boring character-establishing opening, jams it up against a convoluted conspiracy that it obviously doesn't care about, then bumps across a couple of sequences that were apparently art-designed by Russ Meyer's second unit, and leaps without provocation several years into the future (where Kenji has inexplicably become a terrorist), whereupon it destroys Tokyo Godzilla-style. It would be a wild ride if it didn't feel so random--and passionless.

Poorly paced and with nearly all entertainment value crushed beneath the combined weight of its perfunctory direction and spotty acting, the movie's already hefty 2 ½ hours stretch out interminably. Clock-checking becomes an in-film hobby, something you do every couple of minutes just to remind yourself that yes, time is still passing. The truly awful sequences, such as Kenji's A-Team-esque pre-apocalypse gathering of his elementary-school comrades, seem to extend before the eyes like lumpy highways fading into the far distance. And just when you think it's over (which is often—remember those chapter stops) the film will catch its second—or third, or fourth—wind and keep chugging on.

As early as halfway through, and certainly by the time the A-Team moment expends itself, the film's end becomes a sort of promised land, a highly anticipated time after which you will be free to eat, sleep or clean your toenails—anything besides killing time in Kenji's company. Surprisingly it turns out to be a promised land of another sort. Somehow—possibly by using the budget allotted for the rest of the movie's sets, special effects and film stock—Tsutsumi and his crew manage to pull off a preposterous, sometimes thrilling, and genuinely apocalyptic finale.

There were flashes of inspiration previous, but they weren't the film's; they were Urasawa's, somehow poking through Tsutsumi's dead-fish direction. If you were to count the canny insertion of classic American rock tunes (by T. Rex of course, and Bob Dylan) into the otherwise miserable score, then maybe there were a couple of independent near-misses. But the final act is different: the one purely cinematic triumph in a wash of cinematic failures. Conjured-from-air suddenness notwithstanding, the denouement alone almost makes the long slog before worthwhile.

And it's certainly enough to take some of the terror out of the words "sci-fi action trilogy" splashed across the back of the box. If they pack in more of the visual flash on display in those final moments, maybe two more films isn't such a horrifying prospect after all. One can hope, right?