Further tilting the early tilt toward comedy is the director's generous use of slapstick in the opening sequences. But just when you think he's playing it strictly for laughs, he throws in some attention-grabbing scares. Bong has a lot more on his mind than caricature.

The family is introduced in humorous, fairly broad terms, but Bong slyly develops the characters as the film evolves, shedding its popcorn veneer to become something more complex. The transition isn't seamless and the pace noticeably slows as the emphasis shifts to the family's damaged relationships - even as they attempt to hunt down the monster.

However, this unflappable tempo that dominates the movie's midsection succeeds in allowing each character the space to assert him or herself and earn the emotional currency that makes the finale so affecting. Young Ko is particularly impressive in her intensity.

The script is laced with political jabs that include a solid broadside at the perceived paternalism embedded in U.S.-South Korean relations. Bong is also concerned with South Korea's social structure - poking fun at the soullessness of salarymen while championing the working class - and it's no surprise that he studied sociology at the University of Yonsei.

With a subversive streak as wide as the Han and a title open to interpretation, "The Host" confounds our expectations while providing top-notch entertainment. For Bong, the monster movie is an ample vessel, one that he can fill with social criticism while discovering exuberant amusement in the process.