the ones belowBringing a baby into the world can be a joy, but it can be pure hell too. This idea gets ratcheted up with a mixture of paranoia and the trusty old “From Hell” Thriller template. (You know, the “Babysitter from Hell” thriller, the “Roommate from Hell” thriller, etc.) Well, The Ones Below is a “Duplex Neighbors from Hell” thriller, but instead of being just trashy fun, it’s actually executed with much more elegant style, intelligence and concern for character psychology than expected.

Expectant thirtysomething couple Kate (Clémence Poésy) and Justin (Stephen Campbell Moore) live in the upstairs flat of a house in London. When their elderly downstairs neighbor dies, a new couple moves in below and, coincidentally, they, too, are expecting a child. Jon (David Morrissey) is a stern, affluent businessman and Teresa (Laura Birn) is his friendly, younger wife from Finland. The upstairs couple notices something a little odd about the new tenants: Jon and Teresa always take their shoes off outside the door, even of their own precise, pastel-colored home. Setting aside their hyper-neatness, the two women share that special bond—Kate 18 weeks pregnant and Teresa 21 weeks and even more overjoyed than Kate—and become friends. When Kate and Justin have the couple below over for dinner, tension rises and they get the sense that Jon and Teresa might not be as happy as they let on. To make things even more uncomfortable as Jon and Teresa leave dinner, a tragic accident occurs that will change everything.

The feature debut from screenwriter David Farr (2011’s Hanna and AMC’s miniseries “The Night Manager”), The Ones Below is chilly and comparatively subdued when stacked up against thrillers from ‘90s like The Hand That Rocks the Cradle, Pacific Heights and Arlington Road. At 87 minutes, the film is economically written without an ounce of fat. Even the fact that Kate’s mother (Deborah Findlay) is a cold fish is an informative detail that adds context and doesn’t feel extraneous. Having an unloving mother of her own, as well as a history of mental illness in her family, gives Kate fears that she might not be fit to be a mother. It is obvious that there is something to read between the lines—something is off with Jon and Teresa—but how Farr gets to that conclusion is pleasingly twisted and discombobulating. Is Kate crazy or just deprived of some much-needed rest? Or, do Teresa and Jon actually have heinous ulterior motives? That uncertainty and shaky sense of perception are what drive the film.

Even when one has a pretty clear idea of where The Ones Below is headed, the film is cushioned with strong performances. Clémence Poésy (long done with playing Fleur Delacour in the Harry Potter films) anchors the film with a relatability and edge as Kate, while Stephen Campbell Moore finds a certain balance as supportive and then eventually disbelieving husband Justin. David Morrissey is disquieting, even when he’s clearly not all that trustworthy from the get-go, but it’s Laura Bern who makes the most impression. As the sunny, instinctively maternal Teresa, Birn has a way about her that’s constantly changing. On the turn of a dime, she can subtly change from sexy and giving to suspicious and possibly devious.

Indebted to Roman Polanski’s Rosemary’s Baby for obvious reasons—as well as a highly reminiscent la-la-la music score that’s innocent and vaguely menacing—The Ones Below gets points for a classy forging its own path, thick with taut precision rather than routine violence. There is at least one suspenseful scene where a character snoops when they shouldn’t and gets out in the nick of time, but for once, a to-the-death fight between protagonist and antagonist is mercifully nowhere to be found. Instead, writer-director David Farr takes more pleasure in observing the starkly different attitudes of both couples and then puncturing the seemingly idyllic situation. He also makes wonderfully edgy use of muffled sounds on a baby monitor and bathtubs. Attention expectant couples: The Ones Below might not be reassuring, but it’s hard not to get pulled in from start to finish.