LOS ANGELES - There's something about novelist Stephenie Meyer that induces formerly interesting directors to suddenly make films that are slow, silly and soporific.

It happened consistently on "The Twilight Saga," and it happens again on "The Host," once-provocative writer-director Andrew Niccol's adaptation of Meyer's 600-plus-page post-"Twilight" novel that spent 26 weeks at No. 1 on the New York Times best-seller list beginning in 2008.

Aimed squarely at the same tweens who contributed so generously to the bank accounts of everyone who became associated with Meyer's vampire franchise, this one swills in the same sort of thwarted Victorian-style romanticism while indulging a similar moonstruck vibe that can seemingly only be resolved in Meyer's work by selfless female sacrifice.

Not to be deterred, Meyer's army of female fans surely will deliver a big opening, but anything resembling Twilight numbers is a fantasy. Meyer intends to expand "The Host" into a trilogy, but the second book has yet to be published, so any further films in the series remain a long way off.

Once again applying her quaintly old-fashioned morality to her specialty in cross-species attraction, Meyer this time centers on a leading lady whose dual personality hinges on a notion of advanced aliens having taken over the bodies and lives of Earthlings.

Here, the invasion already has taken place, and the aliens essentially have won; only a few fugitive holdouts remain, and the virtual inevitability of total human capitulation dictates the fatalistic attitude of the characters as well as the prevailing mood.

"The Earth is at peace. Our world has never been more perfect," a narrator intones at the outset - and, indeed, everything we see looks pretty darn nifty, a sort of Silicon Valley version of sanitized architectural splendor populated by politely impersonal citizens who resemble Mormon Kens and Barbies.

The upside is that life is easy and stress-free. The downside is that everyone has these weird, glowing blue-and-white eyes that sort of stare without seeming to fix on you or anything in particular; it would be enough to drive you insane in paradise.

In fact, so determined is Melanie (Saoirse Ronan) not to undergo this eye change that she jumps out a window to avoid becoming one of "them." She survives, however, and once she's implanted via simple surgery with some fluid, floating particles that are said to constitute her new soul, she adapts to her revised personality readily enough.

Taking the new name Wanderer with the approval of her overseer, Seeker (Diane Kruger), who hopes to learn the identities of other human renegades, she tries to co-exist with her old inner self, which talks back at her with sharp shrieks, commands and complaints from within whenever "Melanie" disapproves of what "Wanderer" is doing.

Melanie also asserts herself in dreams, which provide a reminder of her romance with Jared (Max Irons), her little brother Jamie (Chandler Canterbury) and others. Her old self gaining the upper hand, Wanderer/Melanie escapes to the desert and ultimately rejoins her little family, which also includes rebel group leader Uncle Jeb (William Hurt), Aunt Maggie (Frances Fisher) and a handsome dude named Ian (Jake Abel) who attracts Wanderer, now called Wanda, while Melanie remains faithful to Jared.

Much hilarity, of uncertain intentionality, stems from the internal battle between the two women whenever Wanda/Melanie gets into a romantic mood with either of her gentlemen friends.

At another point, Melanie disappears altogether, provoking thoughts that she might have perished or, more likely, just gone into a sulk.

The melodrama should benefit from the internal bickering and fateful decision-making of the group, as well as from the urgent search effort undertaken by Seeker and other alien agents.

Instead, this is where the film becomes suffocated by the sort of lethargy and indulgent extension of ennui and indecision that progressively afflicted the "Twilight" series; instead of building dramatic momentum, the film engorges itself on dithering and procrastination, ultimately cocooning itself in an emotional numbness quite at odds with the life-and-death struggles being enacted by the central characters.

From his early work on "The Truman Show" and "Gattaca" through the recent "In Time,"
Niccol has spent most of his career on science- and speculative-fiction material. The futuristic setting imagined by Meyer is comparatively simple and lacking in complexity; she's much less interested in social and ideological structures and advanced technology than in the impassioned impulses of her young heroines, which is the key reason her work has been so overwhelmingly successful.

In the end, this is a survival story, one that pivots on a heroine who not only seeks something to live for but something worth dying for. Unfortunately, it's cloaked in yawningly familiar teen-romance terms and cries out for a seasoning of wit, irreverence, political smarts and genre twists that, given the well-trod terrain, seem like requisites when presenting visions of the near future.

The fine actress Ronan, who was just 17 when filming began, is required to carry by far the most weight and does so capably, though she is partially handicapped in connecting with the audience by those damn eyes. Not so encumbered are the male leads, played appealingly, within limits, by Irons and Abel. (Todd McCarthy/The Hollywood Reporter)

"The Host," an Open Road Films release, is rated PG-13 for some sensuality and violence. Running time: 125 minutes.