EVERYTHING goes backward in The Host, and that's a good thing in one sense: on the basis of the first 30 minutes, The Host delivers everything you'd dream of in a monster movie. Director Bong Joon-ho inverts a time-honored law, showing us the creature at the beginning of the film, not the end. However, the action starts off in the usual way with the christening of a creature in a bath of toxic chemicals. At a U.S. military base laboratory in South Korea, an American officer orders the dumping of some expired formaldehyde down the sink. Then comes the first feeding: a businessman committing suicide by jumping in the river ends up in the submerged devil-fish's gullet, giving it a taste for human flesh.

Finally, about 30 minutes in, a rampage breaks out in a park by the wide Han River. "The Host," as it's called, emerges; a 40-foot-long carpy/squiddy crossbreed; it charges out of the water and snatches up picnickers. In these moments, The Host really deserves its Internet hype. The speedy creature was animated in collaboration by Peter Jackson's Weta and San Francisco's Orphanage; these are probably the best effects any straight-ahead monster movie has ever had. And director Bong had the sense to realize that comedy was the best way to hold this story together. Opposing the Host is a low-born family running a concessions trailer in the riverside park.

The Host has already been called Little Miss Sunshine Meets Godzilla, and like Little Miss Sunshine, the low-income family here is held together by a cute daughter, Hyun-seo (Ko A-sung). She gets stolen right away, but we can feel we haven't seen the last of her when the mass funeral for the monster's victims turns slapstick. Delivering a message via cell phone, the daughter rallies her family to rescue her from the Host's lair. Son Gang-Du (Song Kang-ho) is hardly an action hero. "He dozes like a sick rooster," observes Gang-Du's own father. The dyed-blonde slacker is not only dozy, he is plump from eating the goodies he sells. We realize that there might be more hope for heroism from the one member of the family who actually got anywhere in life, Nam-joo (Bae Doo-na). She's an Olympic archery contender; unfortunately, she has the habit of missing her target whenever she is under stress.

"In the end, the film is a record of [the] fight to the death against the indifferent, calculating and manipulative Monster known as the world," Bong notes. That note of seriousness infects the rest of the film. Finally, the creature makes his most fearsome mutation: he changes into an editorial cartoon. Bong starts to air the grievances of South Korean society—anger at the U.S. military, the lies of the Korean government and the persistence of crime and corruption. All valid topics, but where's the beast? I began to feel as sleepy as a sick rooster, too. If The Host reverses the usual flow of the monster movie by showing the beast early, it also reverses the order of such movies, which start out boring and get more exciting. It would be impossible to carry on the pace of the first 30 minutes without a mammoth budget, but it's the least expensive part of The Host that shorts out first: the comedy.

The Host (R; 119 min.), directed by Bong Joon-ho, written by Bong, Baek Chul-hyun and Hah Joon-won, photographed by Kim Hyung-ku and starring Song Kang-ho and Ko A-sung, opens Friday at selected theaters.

Send a letter to the editor about this story.