Likewise, fanboys (and girls) drooling over Johansson won't be treated to some mindless sexcapade. As a nameless woman, Johansson cruises the streets of Glasgow, using her newfound wiles to seduce men for her nefarious purposes. She's an alien femme fatale, and once she's snared you in her spell, gentlemen, her sultry face clicks back to its poker-faced, robotic demeanor. Look out.

The script for Under the Skin, which opens today in New York City and Los Angeles, and April 11 in select U.S. cities, probably contains a few thousand words of dialogue, max. What conversation there is bridges long silences. Viewers will find no traditional alien versus human action. No chases, or gun battles, or heads exploding with green goo. No little green men or tattooed Klingon wannabes hatching plans to destroy the earth, either.

If Her was all about Scarlett Johansson's off-screen presence–the vagaries of her voice, and what meaning might be read into its inflections–Under the Skin is all about Johansson's looks. And her looking. At you. It's about skin, and bodies, and silent facades. Johansson plays her extraterrestrial invader practically as a mute.

Therefore, fans of sci-fi and Ms. Scarlett, respectively: Be forewarned. But the patient viewer of director Jonathan Glazer's existential, science fictional mediation will be rewarded with an unsettling poetic experience–one that's infinitely more rewarding than the utterly predictable action fare that usually passes for Hollywood's high-concept "alien invasion" schlock.

Glazer, who hasn't made a film in a decade, directed the equally unique and unnerving crime film Sexy Beast (2000). His sophomore effort was the less-well-received ghost story Birth (2004). With Under the Skin, he seems determined to reinvigorate yet another tired genre: the alien-among-us film. Reminiscent of E.T.-out-of-water films such as Nicolas Roeg's The Man Who Fell to Earth (1976) and John Sayles' The Brother from Another Planet, Under the Skin succeeds magnificently. Glazer has crafted an intelligent work of arthouse science fiction equal parts disorienting and disturbing.

Working from Michel Faber's 2000 novel of the same name, Glazer and co-writer Walter Campbell begin their film in medias res (in the midst of things), wisely dispensing with any exposition. Which planet does Johansson come from? How has she arrived on our shores? What does her spaceship look like? Why exactly is she here? None of these ideas are of interest. There are no conversations between characters to fill in gaps.

A good half an hour passes before you feel adequately acclimated to the plot, to the extent that Under the Skin has one. Be patient. Glazer's pace is methodical and unhurried, as studious as Johansson's character is figuring out her new surroundings. It's worth hanging around to see what kind of creepy Pan Galactic Gargle Blaster Glazer has concocted.

I'm wary of giving away too much, but some explanation is necessary to understand the set-up. After a brilliant opening sequence, during which what looks like an eyeball, or lens, is being zapped into being somewhere in space–one that recalls the eerie red camera eye of HAL 9000 from 2001: A Space Odyssey–we're suddenly plunked down in Glasgow. With a black mop of hair, and wearing a trashy fake fur coat, stonewashed jeans and high heels, Johansson is soon seen driving a white van, searching the gritty streets for prey.

"No girlfriend, really?" Johansson asks Bachelor Number 1, a pedestrian she picks up from the roadway after pulling over to ask for directions.

"I don't have a girlfriend," he replies, in a Scottish accent American ears will find almost impenetrable.

"You're very charming. You have a handsome face," she fires back with a smile. "Do you think I'm pretty?"

"I think you're gorgeous," he says.

"Do you?"

"Aye, definitely."

"Good."

In similar encounters, her clunky banter jumps from lines line "I'm looking for the M8" and "Do you live alone?" to "Are you busy right now?" and "I have a place about three minutes from here." Cut to Johansson luring the next cocky dude or poor sap back to her pad for a hookup, alien-style. Of course, she's just playing along, getting what she needs. But what is she really after?

I'll let you imagine what happens next. It's not what you think.

Men, several of them, do fall under her spell. Some are achingly shy, even intimidated. Others are helpless against this alien seductress. They all seem floored by the prospect of their incredible luck. You can practically see the stories forming in their heads, the tall tale of how they scored with some random chick. "Never guess what happened last night. You're not going to fuckin' believe this, man…"

Their reactions feel real, painfully so. They are uncannily candid. Here's why: During the shoot, Glazer had Johansson driving a real van, and interacting with a series of actual non-acting strangers. According to the film's press materials, eight miniature cameras were built into the van's dashboard, headrests, and other hidden locations. They were all wired to equipment in the back of the van, behind a barrier, where Glazer and his team sat watching the eight camera feeds on monitors. Another vehicle followed the van, and after each scene with the men, a crew member would hop out to get release forms from all the accidental actors. (Whether some of the guys recognized Johansson under that tarty make-up was not made clear.)

In the most riveting of these encounters, Ms. Scarlett picks up a man (again, played by a non-professional actor) with a facial disfigurement. But our alien heroine doesn't see or judge him as we might. She's not rattled by his appearance. Rather, she asks, "When was the last time you touched someone."

Adding to the exquisite uneasiness is the soundtrack, composed by classically trained Mica Levi, aka Micachu, of the band Micachu & The Shapes. Her experimental, minimalist score–the crazy lovechild of Ravel's String quartet in F major and Hitchcockian Psycho riffs–combines viola music, synthesized MIDI strings, flute and spare, woody percussion beats. Levi's score punctuates the film like a rhythm track of heartbeats, or heavy breathing. It might approximate the noise inside Johansson's head. Or the siren song of a desperate predator.

Suffuses the entire proceedings is a cloak of suspenseful dread. Much of the movie takes place in a moody dusk, foggy haze or dim overcast, or by the amber light of the dashboard. And a mysterious motorcycle driver who has something to do with Johansson's Mission to Earth bombs around the periphery, never too far away.

But Johansson's character is far from home, as is Johansson the actor. This is a role about as distant from Natasha Romanoff/Black Widow from The Avengers as Mailbu is from Pluto.

"I want to get away from it all," says one man the alien vamp encounters on a stormy, rock-strewn beach. "Because it's nowhere."

The story eventually whisks our Alien in Wonderland off the beaten track of urban Glasgow and into that "nowhere": the wind-beaten countryside of northern Scotland, its desolate heath, snowy Highlands peaks, damp towns and mossy forests. It is here where Johansson begins to abandon her twisted Prime Directive, and where Under the Skin begins to take shape, morphing from random, raptorial encounters to a conflict with Johansson's burgeoning conscience. Hesitant, and terrified, she tries out this idea of being human, of truly inhabiting her body. Our red-lipsticked, low-rent Hooker Who Fell to Earth becomes an alien with a heart of gold. Or, at least, a barely pulsing soul.

Without spoiling too much, it's safe to say her experiment is not entirely successful. But Ms. Scarlett's extraterrestrial stumblings are poignant, and heartbreaking, and serve to remind each of us, each life form, what constitutes the human condition. Is it our capacity for mercy, or charity, or love-making? Or our ability to fake it, get what we want, and just play along?

Perhaps we are most human when we've finally decided to give up our evasive or dastardly ways, come down to earth, and finally be real.