Despite its South Korean origin, “The Host” exposes a troubling trend in the American movie industry. Last year, Mark Cuban’s Magnolia Pictures bought the rights for “Gwoemul,” the highest-grossing movie in South Korean history, which was marketed in its homeland as the complex character-driven film it is. Magnolia proceeded to design a movie poster that featured a human-wielding tentacle emerging from the ocean surrounding block letters pronouncing “The Host,” a title that suggests a film that aims to do to dinner parties what “Hostel” did for budget student travel in Europe.

Fans of trashy monster films may come to theaters for the giant carnivorous reptile, but they will discover one of the best movies of the year, with the attention to detail, stunning visuals and respect for its material that one would expect of art-house fare. Even though the stage has been firmly set in the sci-fi realm, “The Host” always maintains a sense of realism and accepts the consequences of its plot choices (in the same way that, for example, “Lost” does) — in other words, it’s a film based in science fiction, but grounded in reality.

What is so remarkable about “The Host” is that it succeeds in so many genres — it’s a verifiable classic monster flick, but also excels as a post-Katrina, post-tsunami, post-9/11 commentary on how we respond to disaster and political activism; a satire of cultural paranoia, international cooperation and environmental neglect; a character-driven story of redemption, and, most impressive of all, a comedy.

The movie opens at a U.S. (of course) Army Base in Korea, as an Army officer orders a protesting Korean subordinate to inexplicably pour dozens of bottles of “dirty formaldehyde” down the sink into the Han River. The plot device may seem bizarre, but the scene is actually a reenactment of a 2000 scandal that continues to cause outrage in Korea, as the officer who ordered the disposal has still not served his prison sentence.

Flash forward to 2006 and the Park family, who run a snack bar along the Han River. A giant mutant reptile — a creature with the size of Godzilla, agility of Spiderman and appetite of Kirstie Alley — emerges from the river to snack on some tasty Koreans and kidnap the youngest member of the Park family, Hyun-Seo (played by the precocious Ko A-sung, aka the Asian Dakota Fanning). The Park family believes she has been eaten until a day later, when they receive a call from Hyun-Seo using a cell phone she took from a corpse and she informs them that she is stuck in a huge sewer with the monster’s other victims. While the family is trying to hunt down the monster and track down Hyun-Seo, the government is on their tail, as they believe the family has become infected and made delusional by a mysterious virus “hosted” by the monster.

The chase provides plenty of material for the well-developed Park family. Korean A-list actor Song Kang-Ho stars as Gang-Du, Hyun-Seo’s father, whose difficult life has led to neglectful parenting but an endearing personality. Byeon Hee-bong gives the film’s most captivating performance as Gang-Du’s remorseful, determined father, who gives one of the most entrancing speeches ever put on film to his other two children. Throughout the film, each character, including Hyun-Seo, overcomes the demons that plague him or her, but not in a way that hits you over the head.

The film develops more themes than most movies twice its length could even hint at. There’s enough provocative material packed in there to think about for years to come, beginning with the central question the film’s title poses: Who really is the host of the virus?

“The Host” balances its heavy themes with comedic elements that keep the film from dragging. Skilled director Bong Joon-ho exposes the extreme and ridiculous nature of many emergency protocols. A memorable scene featuring a stumbling policeman in an oversized biohazard suit and hysterical crying turning into fighting effectively parodies the exaggerated melodrama with which these situations are often portrayed, while also amusing the audience as thoroughly as “Blades of Glory” could in the next theater over.

“The Host” was the most expensive South Korean movie in history, but that only amounted to $10 million. Despite the relatively small budget, the result is a stunning and uniquely beautiful movie that effectively uses CGI as an accessory rather than a spectacle, and the final battle scene includes some of the most incredible shots to appear in a modern action film. Sadly most Americans will never hear of, let alone see, “The Host.” Magnolia’s marketing strategy failed, and, despite critical raves, the film has had only mediocre domestic box office returns. Make sure, however, to seek out “The Host” at your local video store at any cost — you’ll probably find it jammed between “Lake Placid” and “Snakes on a Plane.”