Fans of “Gone Girl” who have been patiently waiting for star Rosamund Pike to sink her teeth into another delectably devious role, rejoice. J Blakeson’s “I Care a Lot” provides the best showcase of Pike’s darkly ambitious drive since her Academy Award-nominated breakthrough in 2014. None of this is intended as a slight to her work in the interim, to be clear. But there’s just something joyous in seeing that devilish twinkle return to Pike’s eye as she charges forward to fulfill her objectives, regardless of the pain it causes others or the lies she must tell along the way. She’s the key component in the project pulling off the increasingly rare balancing of visceral entertainment and intellectual stimulation within the adult dramatic thriller.

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Pike plays Marla Grayson, a professional legal guardian undaunted by ethical guidelines so long as she can skim a few extra dollars from her aging clients. She’s a satirical encapsulation of American capitalism gone haywire in the mold of Chuck Tatum from “Ace in the Hole” or Lou Bloom from “Nightcrawler,” antiheroes who spy profit where others see pain. By the time “I Care a Lot” picks up with Marla, she’s already amassed a small empire on the backs of the Social Security-collecting set.

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But plenty is never enough for a hungry businesswoman like Marla. Rocking a severe bob cut and pulling strong hits from her large vape pen, she cuts a war path with her latest mark: Dianne Wiest’s Jennifer Peterson, a wealthy senior beginning to show early signs of dementia. With no apparent family to claim responsibility for her care, Marla might as well have dollar signs in her pupils. Like many who make their fortunes off the misery of others, she’s far from contrite about ruthlessness of her professional maneuvers. If anything, she’s proud of it and wears the scorn of the people she outwits as a badge of honor. Blakeson documents her well-oiled process for dumping her clients in elder care and extracting monetary value from their assets with aesthetic briskness that matches the precision of Marla and her business partner Fran (Eiza González).

“I Care a Lot” zips along with thrilling efficiency in this early section focused squarely on Marla. Pike’s performance is the stuff of goosebumps, perversely tickling the dark side of the funnybone at the same time as it sends a chill up the spine. With the limelight squarely fixed on her, it’s easier to see Pike’s bold, distinct choices as an actress and how they shape such an indelible character. Because she cuts such an imposingly large and cleanly calibrated presence across the film, the brute force of the mechanisms through which she simplifies complex questions of legality, sanity and aging become quite terrifying.

As he introduces more characters and complications to the narrative, Blakeson does manage to keep the film moving at a steady, exciting clip. Marla makes the miscalculation of pissing where she eats, figuratively speaking, with Jennifer and her mysterious fortune. Her aggressive actions trigger a response from another group with few scruples and a lot of muscle: the Russian mob.

“I Care a Lot” introduces a colorful menagerie of associates who attempt to persuade Marla to change course. Some, like Chris Messina’s Dean Ericson, a two-bit mob lawyer with a cheesy smile Dean Ericson, make a real impression while fitting in neatly with the tone of the film. Others, like Peter Dinklage’s Roman, a shady businessman with a manbun, feel a little too hammy even for this go-for-broke satire. Blakeson’s first feature, “The Disappearance of Alice Creed,” suffered a bit from a similar disconnect between taut direction, clever plotting and overly broad characterization.

The film does not suffer much for these slight incongruities. “I Care a Lot” glides like a classic studio thriller thanks to top-notch production values, from the bright colors that explode off the screen to a synthesized score that throbs tensely throughout. And, of course, there’s the Rosamund Pike factor. It’s not that anyone else in the movie isn’t good. But no one ever quite matches the unrivaled brilliance of Pike when given a clear runway to strut her skills. Seeing her in peak form nimbly navigating the tonal minefield of this late stage capitalism critique is an absolute delight. [B+]

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