A monster movie for our terrorism and biological warfare-shrouded era, Bong Joon-ho's The Host delivers high-octane thrills while cannily exploiting contemporary political fears, with some inspired visual humor amplifying its overriding mood of popcorn-movie excitement. When a U.S. military scientist orders an immense stash of toxic formaldehyde to be dumped down the drain, the result is the birth of a mutant amphibian/reptilian beast in Seoul's Han River, along which citizens picnic and Hee-bong (Byun Hee-bong), with the help of immature adult son Kang-du (Song Kang-ho), operates a food stand. Kang-du is the doting if irresponsible father to seventh-grader Hyun-seo (Ko A-sung), and with a deft touch and attention to small details (Kang-du hiding a stash of money for his daughter's new cellphone behind a stuffed animal head; his surreptitious ingestion of a customer's squid leg), Bong quickly paints an endearing and comical portrait of his central familial unit, a quirky, loyal, financially strapped clan which, it's later revealed, also includes unemployed college grad Nam-il (Park Hae-il) and dawdling archer Nam-joo (Bae Doo-na).
The director has a knack for vividly conveying the essence of his ragtag protagonists through minor moments, and in his film's sterling intro, displays a sure-handed—and, to some extent, Spielbergian—gift for eliciting empathy for his less-than-perfect souls. Such attention to character doesn't waver once the story's beast emerges from the Han to wreak havoc on unsuspecting onlookers, as The Host remains firmly fixated on the personal even as its propulsive momentum picks up steam and the inhuman fiend, traversing land like a leaping dinosaur and swinging underneath the city's bridges with Alien-like rapidity, swallows Hyun-seo whole and then deposits her via regurgitation in a dank sewer pit.
Bong's camera glides effortlessly through intensely choreographed set pieces, utilizing breathtaking pans and potent slow-motion to give the action a vitality that's further enhanced by his frequent insertion of amusing asides (a girl wearing headphones proves oblivious to the fleeing crowds; a Hazmat-encased military man clumsily falls down and then even more clumsily tries to act cool in the face of embarrassment). And yet thanks to sterling performances by both Song and Hee-bong, the hectic film maintains a consistently affecting human dimension that Bong's mirthful mayhem thankfully never engulfs, with its charming portrait of parents and children epitomized by a scene in which Hee-Bong earnestly beseeches the relatively well-adjusted Nam-il and Nam-joo to treat their sibling Kang-du with love and respect while the duo, exhausted from their adventure and bored by the lecture, doze off.
After the creature is identified as the carrier of a deadly new virus (hence the movie's title), the military enacts a multi-tiered plan that involves quarantining anyone who's had contact with the monster, setting up armed roadside checkpoints, fumigating the streets, and ultimately allowing the U.S. government and WHO to blast the metropolis with a bacteria-annihilating chemical weapon known as Agent Yellow. Issues of foreign invasion, homeland security, pollution, pestilence, and government misinformation soon begin peering out from beneath The Host's B-movie exterior, imbuing the sci-fi proceedings with haunting present-day parallels. Nonetheless, Bong's creature feature stops far short of mutating into a sermonizing, this-means-that allegory, instead allowing such vague analogies to simply help root his out-there story in a believable, recognizable contextual framework.
The virus's man-made origins—and the government's excessive response to the plague-like threat (which, it's eventually revealed, is nonexistent)—may, ultimately, illuminate the catastrophic pitfalls that await those foolish or arrogant enough to seek easy solutions for serious problems. But in Bong's compassionate hands, The Host's wider geopolitical warnings mainly serve as counterpoints to his more intimate (and touching) concerns: the virtue of hard work, the nobility of selflessness, and the unrivaled heroism of being a dutiful, devoted, and loving father.