Xam'd is not a clean series. It's full of fits and starts and messy dead ends, characters abandoned and characters added and situations and relationships ended suddenly and unsatisfactorily. It is, in short, a mess. If you're to go by the litmus test of watchability, it's also an undeniable success: somehow by the end of every episode you want very much to go on to the next.

In some ways that's exactly because it is messy. You can never be entirely sure where the series or any one of its characters is going to end up. You'll be getting used to the idea of Akiyuki spending the series as part of a crew of quirky mail carriers when his new life ends with a crash. A couple of episodes later, just as you've gotten comfortable with his tandem journey with Nakiami, it too meets a violent and untimely end. That Haru would search for Akiyuki and Furuichi would stew in jealousy are to be expected; that the result would be their joint enlistment isn't. It's a pattern that reaches right down to the bit players and all the way to the end of the series. Whether plot or character, chances are they're about to surprise you somehow—not always pleasantly, but that's part of what makes it so interesting.

Of course, some of what makes the series unpredictable is that a lot of it makes zero sense. It would be a fool's errand to go into it all; the series is a regular feast of things bizarre and illogical. There are those that arise from a mere lack of explanation, like the black blob that menaces Nakiami at one point or the ill-defined world-resetting mechanism that the climax is built around. There are those that are born when the series abandons or forgets something: orphaned scenes of children in bird-suits harvesting souls for no apparent purpose, of people swallowing green glowing orbs for vaguely mystical reasons. Some come about when reality gets bent far enough that reason breaks down—Nakiami harvesting a soul from a mental projection of Haru's mother while inside her sister Midori's mind, for instance. And then there's the stuff that's plain batsh** crazy. Things like inexplicable fossilizing rain, or the deranged fates of pretty much all of the villains.

There are defenses one can marshal against the onslaught of nonsense. Close attention reveals some non-sequiturs to be more sensible than they first seem, and with a little extra effort one can fabricate plausible explanations for a lot of what goes on—especially when there're no competing explanations, which is much of the time. If you're desperate, flimsy ad hoc explanations sometimes get thrown out during the chaos. It is easiest and most satisfying, however, just to go with it. Don't try to make it adhere to logic: ride that wave of insanity; let it carry you around blind corners to unexpected places.

You'll have a lot more fun if you do. Sure not everything makes sense. Sure the show bails on plots and characters whenever it feels like it and returns to them when it wants or not at all. Sure it makes moves so big and unexpected that they cleave the series right in two. But one thing you can say, it's rarely boring. Boring happens when you can see what's coming. You can't predict that a character will snatch his own head off, or that Akiyuki's trip home will somehow end with him, mind-wiped and perched atop a water tower, conversing with a floating eyeball that speaks in an Emperor's voice.

Boring also happens when you don't care what's coming. The series is good about connecting its bold and occasionally crazed plot turns to its characters, and specifically to the parts of them we actually care about. It delights in twisting Akiyuki, Furuichi and Haru's initially easy friendship into evil and unrecognizable shapes. Severing hard-earned relationships with a savage sideways yank of the plot is a favorite ploy, as is teasing with long-delayed reunions. We grow attached to decent Akiyuki, strong-willed Haru, awkward Nakiami; we get very invested in the damaged adult love of Akiyuki's parents. Maybe there're gaping holes all over, maybe they flaunt logic, but we still hang on the divergences, convergences and hairpin turns of their paths. And when the time comes to conclude the whole circus, disasters and conflicts alike sputter out in flashes of mystical mumbo-jumbo, but the characters always get their due.

Xam'd isn't above borrowing from its peers, and it isn't shy about broadcasting its influences. From Eureka Seven it borrows its initial ship-on-the-run plot, as well as the annoying kids and even the rainbow effect used when ships take off. There's a hint of Studio Ghibli in the character designs and settings (especially those with petrified Xam'd), which is appropriate given all the flying machines. The flying machines take their mode of locomotion straight from Escaflowne, from which Michiru Oshima's score also takes its inspiration. It isn't on par with Hajime Mizoguchi and Yoko Kanno's masterwork, but it is very good: its orchestral themes have wings and its vocal interludes are beautiful. It's the kind of score that doesn't just support its series, but elevates it.

The same could be said of the series' execution as a whole. Its fictional world is a broad one, with religious, military and political institutions from multiple nations playing multiple parts, and locations that span seas and mountains and forests, great cities and humble towns and idyllic villages. BONES is careful to give each institution its own distinctive costume, each nation their own technological base, and each culture their own custom of dress and decor. The organic weaponry of the Northern Government is a particularly imaginative touch, made both fascinating and repulsive by the fleshy mobility of BONES' animation. Action scenes are furious and well-constructed, with generous helpings of lovingly rendered destruction. Less flashy but equally important, characters are given a wide range of motion and emotions. During reunions joyful and tragic, moments introspective and bombastic, the characters' emotions register clearly and, in a few special cases, very powerfully.

Those few special cases—Akiyuki's three(!) reunions with Haru, his mother's dash to meet him when he returns, Ishu's partings from Nakiami—are the series at its very best: when its strong character dynamics conspire with bizarre twists of fate to whack us hard in the heart. Not unexpectedly they put a heavy burden on their actors. More surprisingly, the actors tend to be up to it. Performances overall are variable. David Matranga is a little flat as Furuichi, Monica Rial is solid as Haru, and Blake Shepard is appealing if unspectacular as Akiyuki. Most of the remaining cast falls within that range, the main exceptions being Chris Hutchison, who unwisely discards the primary villain's clear diction, and Corey Hartzog, who has difficulty making his child sidekick sound natural. When the script calls for intensity, however, they rise pretty much uniformly to the task. Sentai Filmwork's dub script is so faithful to the subtitles—with only slight variations to adjust for lip flap—that one half suspects that they're dubtitles.

Is Xam'd uneven? Is it questionably plotted and dangerously volatile? Did its writers ad-lib the whole thing instead of planning it? Respectively: yes, yes, and quite possibly. Logic, cohesion, and structure are not its strengths. Courage is, and flamboyancy. It isn't afraid to move, move big, and keep moving. They say a life lived safely isn't lived at all. You could say the same for anime series. Xam'd lives; not prettily or flawlessly, but colorfully and forcefully.