Watch ‘I Care a Lot’ Review: Rosamund Pike and Peter Dinklage Are Riveting in a Scam-Artist Thriller That Won’t Let Go

“I Care a Lot” is a sleekly unnerving thriller. It’s built around a scam just plausible enough to give you pause, and a protagonist who’s so efficient in her diabolical ruthlessness that you can scarcely take your eyes off her vicious amoral glow. Rosamund Pike, in killer suits and a bob so precise it looks like a blonde helmet sliced with a laser, plays Marla Grayson, a conservator who’s really a con artist. She’ll stand up in court, radiating a beam of articulate compassion, and argue that a senior citizen can no longer look after him or herself and should therefore be placed under Marla’s care. She then becomes their guardian — and sticks them in a rest home, so that she can slowly but surely suck away their assets. She’s the film’s protagonist, but she’s no mere grifter. She’s a sociopath, a predator who will toss someone’s life into the trash with a duplicitous grin of pride.

Because here’s the real crime: Some of the wards Marla takes under her wing are still perfectly capable of taking care of themselves. Early on, she shows up at the door of Jennifer Peterson, a nice old lady played by Dianne Wiest with so much soulful gumption that she’s like a quiet American Judi Dench. With several policemen in tow, Marla leads Jennifer away, because she’s got the legal papers to do it. They state that Jennifer is showing symptoms of dementia, and they’re signed by a physician, Dr. Amos (Alicia Witt), who is Marla’s partner in crime.

It’s not often that a movie’s production design creates something outwardly emotional, but Jennifer’s home is a lived-in thing of beauty: tranquil and aesthetic, painted a lovely flat shade of royal blue, adorned with knickknacks that suggest it’s a nest she’s been feathering for decades. It’s the kind of “modest” home that now fetches a pretty penny, and J Blakeson, the writer-director of “I Care a Lot,” creates a richly unsettling sequence in which Jennifer is led away from her quaint domestic oasis and driven to the Berkshire Oaks Senior Living facility, where she’s greeted by a row of creepy friendly nurses and assistants, stripped of her cell phone, and — of course — put on a cocktail of tranquilizing drugs. (Moments later, we see her house being emptied, painted, placed on the market, and sold.) If she demands the use of her phone or gets angry about something or asserts that she doesn’t need assistance, she’ll now be seen as a dementia patient who has lost control of herself. It’s “Requiem for a Dream” meets Kafka.

You watch this sequence with a knot in your stomach, as if Jennifer were your own parent. “I Care a Lot” hinges on an outrageous criminal racket, but it’s the kind of suspense film that hits small nerves of social reality — not in a heavy way, but under the surface.

Watching Jennifer trapped in her assisted-living prison makes us question the whole system by which old people are consigned to — and sometimes dumped into — rest homes. The fact that Marla achieves all this through the courts, which collude with her in shunting aside the blood relatives, carries its own eerie specter: of a society increasingly controlled by a network of medical and legal bureaucracies.

And then there’s Marla herself. Her whole personality is a sinister corporate construct, brought to brazen life by Rosamund Pike, who shows far more star quality here than she did in “Gone Girl” (though the roles are in certain ways similar). Marla’s actions are over-the-top villainous, and the film works up so much sympathy for Wiest’s beleaguered Jennifer that it’s clear whose side we’re on. But then there’s a twist: the introduction of an underworld businessman, Roman Lunyov, played by Peter Dinklage with a furious twitch of icy intelligence, who has a crucial connection to Jennifer. He dispatches an attorney to Marla’s office, and the lawyer (Chris Messina) looks at Marla with juicy contempt and calls out her scam. He offers her $150,000 to let Jennifer go, making it clear that if she won’t cut a deal, ominous consequences will follow.

We expect her to back down, since it’s clear that the threat is no joke. Yet she remains unfazed, almost amused in the face of danger. “I Care a Lot” is a thriller about what people think they can get away with — a suspense film that’s really a parable of power. Marla’s belief in herself may seem nuts, but it starts with her perception that the world is designed to make women back down. “If you can’t convince a woman to do what you want,” says Marla, speaking to her lover and criminal assistant, Fran (Eiza González), “then you call her a bitch and threaten to kill her.” Later, when Marla is tied to a chair, negotiating with a man who would kill her in a cold heartbeat, she remains fearless, and the more our antipathy melts into…admiration. She becomes both villain and heroine, as we develop a rooting interest in her scary cunning.

J Blakeson has just made a couple of low-grade genre movies (“The 5th Wave,” “The Disappearance of Alice Creed”), but I’m here to say: He’s a major talent. “I Care a Lot,” while it could have used a catchier title, is a riveting film with its own hairpin logic. Blakeson wrote the screenplay, and his dialogue has a subversive snap. And when he finally gets around to staging an action sequence, it’s a doozy — not because it’s so spectacular (it involves a car crashing into a river), but because he takes his time and has you hanging on every moment. (That’s what Hitchcock did. It’s called suspense classicism.) Blakeson has written a terrific role for Peter Dinklage, who gets to show off his own propensity for stylish power games, but what the filmmaker teases out in Rosamund Pike is a revelation. Together, they create a femme so fatale that she seems to have left a century’s worth of movie nice girls in the dust.