Robert Rodriguez's "Sin City" was an eye-frying accomplishment — the movie lifted Frank Miller's stark noir fantasy world straight off the comic-book page and deposited it directly onto the screen. Zack Snyder's film version of "300" — Miller's 1998 graphic-novel recreation of the bloody battle of Thermopylae in 480 B.C. — surpasses that already considerable feat. Snyder's movie improves upon Miller's celebrated graphics. Here, the shadows seem denser, the colors more radically concentrated, and every image throbs with drama — even the steely, shifting skies are troubled and turbulent. The picture marks a new peak in digital visualization — you feel you're truly in another world. The film's concerns, like those of Miller's book, are narrow: It wants only to submerge you in a sea of heroic brutality. It does just that one thing, but it does it with feverish expertise.

The story concerns the invasion of ancient Greece by an enormous army, a quarter-million-men strong, under the command of the Persian god-king Xerxes (Rodrigo Santoro). Several thousand Greeks, few of them seasoned soldiers, hasten to the narrow mountain pass at Thermopylae, hoping to obtain from the cramped terrain a tactical advantage over the enemy's sheer numbers. For two days they manage to repel the invaders. On the third day, a treacherous shepherd betrays the Greeks' position, and as the Persians begin to surround them, the leader of the defenders' most battle-hardened contingent, the Spartan King Leonidas (Gerard Butler), dispatches the bulk of the Greek forces to return home to mount further defenses, while he and his 300 men remain at Thermopylae to fight on against impossible odds, to a guaranteed death.

Snyder has wisely watered the testosterone in which Miller's story is marinated with some less-ferocious diversions. He cuts away from the battle occasionally to return to Sparta, where Leonidas' wife, Queen Gorgo (Lena Headey), struggles to foil the traitorous machinations of a duplicitous councilman named Theron (Dominic West). There's also some wonderfully lurid debauchery in a harem, and a visit to a mountaintop where a group of hideous degenerate priests contemplate the erotic writhings of a beautiful young Oracle. (One of them stoops to lick her head with his diseased tongue — nice.) Apart from those moments, though, the movie is all blood and guts and raging spectacle. Spears rip through chests, heads fly off of necks, and gouts of blood spurt through the air. There's a tree filled with arrow-pierced corpses and a wall of bodies stacked 15 feet high, waiting to be pushed over onto unsuspecting Persians. The hyper-stylish mayhem is virtually nonstop.

There are also some indelible images, chief among them the nine-foot-tall Xerxes himself, who is carried into battle on a platform, complete with throne, by a detachment of "Immortals" — an extra-vicious breed of soldiers in eerie silver masks and black turbans. With his shaved chest and plucked brows, and his baubles, bangles and nose rings, Xerxes exudes a sexual presence that's too deliriously campy to qualify as ambiguous, and he brings a giddy twinge to every scene he's in. Equally memorable is his monstrous executioner, a flesh-mountain of a man whose forearms have been honed into blades. And there's a phenomenal extended sequence in which Xerxes' invading fleet of ships is swallowed up by the sea, which ranks pretty high in the history of cinematic naval imagery.

It's great that there's so much to watch in "300," because there's not a lot to think about. The story seeks to elucidate a single idea: that some things are worth not only fighting for, but dying for; that selfless heroism is a core value of human civilization. It's hard to argue with this, although occasionally you might long for a little elaboration, if not nuance. But then another severed noggin goes flying by, and the thought passes.

"The Host": Fish Out Of Water

This South Korean box-office monster is an overlong but lively descendant of such antique beastie features as "Godzilla," "Them!" and "Monster From the Ocean Floor" (all from 1954, the launch year for irradiated cinematic mutants). Unlike those low-budget classics, though, director Bong Joon-ho's movie benefits from a rather large budget, much of it plowed into creating the rampaging behemoth of the title, an alarmingly acrobatic creature that suggests a giant monkfish unwisely interbred with a snarling Warg from the second "Lord of the Rings" movie. (The seamless integration of this vile entity into the film's live action is the work of some top-rank effects houses, including the Orphanage and "Rings" director Peter Jackson's Weta Workshop.) In the tradition of its underfunded forebears, "The Host" does have its flat moments, most of them huddled together in the middle of the movie; but it also has true genre fizz and conviction, and some amusing ideas.

The picture takes off from a premise that would seem strained were it not based on an actual 2000 incident in which the U.S. military dumped 20 gallons of carcinogenic formaldehyde into the Seoul sewer system, which drains into the Han River, which in turn flows through the heart of the city. The movie opens six years later on a bank of the Han, which is thick with afternoon picnickers munching snacks provided by a small food stand. The stand is run by a grandfather named Hee-bong (Byun Hee-bong), the affable patriarch of a family that includes a grown daughter named Nam-joo (Bae Doo-na), whose archery skills will later prove useful; two sons, the ornery Nam-il (Park Hae-il) and the slovenly Kang-du (Song Kang-ho); and Kang-du's 13-year-old daughter, Hyun Seo (Ko A-sung). Kang-du is delivering an order of grilled squid to a group of lounging locals when all eyes are suddenly drawn to a nearby bridge, from the underside of which is hanging ... what, an enormous sack of sickening sludge?

Of course not. It's a mutant amphibian in a foul mood, and within moments it has dropped into the water and clambered up onshore, striking terror, wreaking havoc, and swatting around those luckless folks who are fleeing too slowly. Then it scoops up little Hyun Seo, leaps back into the river and oozes off with her. The rest of the movie follows her family's quest to save her. This is somewhat slow going at times, especially, as I say, around the middle. Fortunately, the creature has a convincing dimensionality — boats rock when it dives into the water, dust clouds billow up when it rolls down a slope — and this keeps things interesting. (And persistently icky: The monster's unlovely mug recalls both the multi-mouthed drooler of "Alien" and the maw-faced sandworms of "Dune.")

The most interesting thing about the picture, however, is the jolly contempt it shows for all forms of authority, from bossy cops and officious medicos to the parasitical media crews that frantically canvas the mayhem. When a frightened man demands to be told what's going on (all monster information is being controlled by "the Americans"), an imperious hazmat technician suggests he turn on the news to find out. When the hospitalized Kang-du describes his hair-raising encounter with the creature, a doctor says, "Jesus, why didn't you contact the police, or a television station?" And after the terrified Hyun Seo makes cell-phone contact from the sewer where the creature has stashed her, and her grandfather begs cops to track the call, he's told, "You think we do that for just anybody?"

Very soon, the know-it-all authorities conclude that the creature is actually a "host," the carrier of a deadly new virus, and that the only antidote is an American bio-warfare substance called "Agent Yellow," which is soon being sprayed all over town, to the consternation of the citizenry. Do the authorities have any idea what's really going on? Their record, by this point, is not reassuring. (The actual nature of the virus turns out to be one of the movie's droller jokes.)

Despite the high-tech monster, and the rich, rain-drenched mood slowly built up by cinematographer Kim Hyung-goo, the director seems to reject big-budget slickness on principle. Some of the scenes — like the one in which distraught family members slide around on the floor in gibbering grief — are amiably sloppy, and a pre-monster riverside sequence flirts with listlessness. The movie could have used more tautly designed scenes like the one in which Hyun Seo quietly attempts to escape from the pit in which she's imprisoned — and suddenly finds herself suspended in midair, in the slimy embrace of the monster's tail. The picture also would have benefited from more of the fairytale wonder that suffuses the final shot, of the riverside food stand glowing hospitably on a dark snowy night.

"The Host" doesn't feel like a classic monster movie — it's not really scary enough. But it does feel fresh, and it has a raggedy esprit. It's not embalmed in its genre. For those who might find this insufficiently interesting, well, that third "Hills Have Eyes" retread is only two weeks away.

Check out everything we've got on "300" and "The Host."

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