In the future, hunger, violence and money have disappeared. Lying is unthinkable. And stealing — from the place where one acquires one’s every need, a building labeled "Store" — is pointless. Because we’re all wearing spotless white suits and driving shiny, chrome-plated Lotus Evoras. Well, a lot of us are.

Humanity has been "perfected," thanks to the aliens. They came, they moved in — not just onto the planet, but into our bodies. And now, the human race is all but extinct, our bodies governed by seemingly benign conquerors. Free will dies as our corpses become "hosts" to the "souls" of those who apparently know what’s best for us and make us serve "the common good."

But Melanie (Saoirse Ronan) is resistant to this body snatching. She debates and wars with the old soul, "Wanderer," who has invaded her most personal space — her mind. Melanie wants to shake free of these alien bonds, to find her younger brother Jaime, her boyfriend Jared (Max Irons) and the resistance movement they’ve run off to join.

That’s the world of "The Host," Stephenie Meyer’s "Invasion of the Body Snatchers" follow-up to "Twilight." On screen, it’s just another chaste, action-starved and absurdly talky action romance. And it has to be. Most of the movie is a heated argument that takes place inside poor Melanie’s head.

Writer-director Andrew Niccol ("In Time,""Gattaca") finds some sarcastic laughs in that most eye-rollingly anti-cinematic situation — a few of them intentional. And Ronan ("Hannah," "Lovely Bones") struggles gamely against the limitations of staging bickering interior dialogues. ("This body is MINE." "I hate you. If only I could HURT you.")

Melanie cannot hurt Wanderer. But she can persuade her of the longing Melanie has for Jared, her need to save her brother (Chandler Canterbury), her desire for freedom. Melanie/Wanderer find that fabled colony where a lot of guys of the same build and light-brown hair color (Irons, Jake Abel and Boyd Holbrook) are fascinated by this new "soul" now in their ranks. Another Meyer love triangle is set up. OK, quadrangle, if you count Wanderer. Meanwhile, one obsessed "seeker" among the souls (Diane Kruger) is determined to find the missing Wanderer and wipe out the last of the resistance.

The action beats — chases, hunts, fights and shootouts — are few and far between here. Too many characters (William Hurt is Uncle Jeb, patriarch of the resistance) have to spend too much time on exposition — explaining who they are and how this Brave New World works. The young would-be lovers talk and talk and talk. The leads generate little heat and the look-alike lads (that’s a casting blunder) try to figure out if it’s Melanie or the sympathetic alien who took over her bod that makes her irresistible to the resistance.

The film’s slack pace allows us to ponder Meyer’s ever-present big themes — body image, guilt, free will, right and wrong as it relates to groupthink. Like the argument going on in Melanie’s head, Niccol struggles to come to grips with his interpretation of those themes. Is the Mormon romance novelist quietly rebelling against a hierarchy, or endorsing it? Is Niccol in revolt against Meyer’s myopia?

That makes for a meandering, misshapen film where big ideas stolen from "Invasion of the Body Snatchers" fail to ignite because the sparks are smothered in tedium, the romance drowned out by all the arguing going on in that confused girl’s head.