Passing, one of the most unassuming and unpretentious films to premiere at this year’s Sundance, might have been the festival’s best. As noted by The Guardian way back in 2018 when the project was announced, the film’s subject matter revives a cinematic trope that used to be fairly popular in the ’40s and ’50s: non-white characters “passing” in order to enjoy the privileges of whiteness. Odd, perhaps, to think of such a thing as a “trope,” as “popular,” or as fodder for melodramas like Pinky or comedy-musicals like Show Boat. As it pertains to real life, the practice is decidedly more complex than its depiction in film would lead one to believe. Passing is one of the few to treat this social maneuver with care and restraint, and in doing so it instantly becomes the defining film on the subject.

The film follows Irene (Tessa Thompson) as she reconnects with her childhood friend Clare (Ruth Negga), discovering that Clare has been passing for some time. She’s married to an unsuspecting white man (Alexander Skarsgård) prone to a matter-of-fact hatred of non-whites, and their child together was “thankfully” equally so light-skinned as to not give her away. Clare is immediately fascinating to Irene, and Irene’s obsession only grows when her own husband (André Holland) seems to take an interest in Clare as well. The criss-crossing relationships become fraught with ambiguities, true motivations and intentions often shrouded by a social façade that each character carries like a shield.

A great many films use ambiguities of this sort as first- or second-act leverage. Will they or won’t they? Are those two characters having an affair? What about those two characters? Passing introduces these possibilities but brilliantly declines to offer easy resolutions to many of them. The business of passing, it turns out, is hardly black and white. When Irene’s husband appears to be whispering something to Clare, a lesser film would have played out the first thing that leaps to mind: he’s attracted to her because of her perceived whiteness. Passing does not gloss over that idea, but it also doesn’t ignore such possibilities as Irene herself being attracted to Clare because of her perceived whiteness. And we’re offered the flip side of the coin, too, when Irene’s neighborhood friend (Bill Camp) finds himself more intrigued by Clare’s “exoticism” when he discovers that she’s not white.

While this marks Rebecca Hall’s first venture from the world of acting into the world of directing, the confidence on display in these moments of ambiguity shows an understanding behind the camera that belies this project as a “debut.” It helps that Nella Larsen’s 1929 source novel is sparse and to-the-point, and the black-and-white, 4:3 Academy ratio presentation befits this streamlined narrative. For a film that could easily have preached the tribulation of race in America, Passing‘s restraint instead powers a much more interesting deconstruction of racial roles within shifting social circles.

Negga and Thompson are both spellbinding, with the former particularly volatile as the seemingly-innocuous Clare. The chemistry between the two is where the real fire burns, with every curious glance from Irene betraying a bit more of her fascination with the girl who used to be just like her. And even without critiquing the actual performance from Skarsgård, his mere presence is instantly impactful. He’s played outwardly-charming/inwardly-despicable so well and so often that we immediately feel the threat at hand when Clare introduces her husband. His is the sole unambiguous role in this story of ambiguity, probably because there always seems to be an outwardly-charming/inwardly-despicable white man exerting dominance over the lives of others.

That aforementioned Guardian article, while providing a fairly exhaustive history of passing on film, did overlook one notable modern effort: 2003’s The Human Stain, adapted by Robert Benton from the Philip Roth novel. Stain is a film I quite like and a novel I deeply admire, though the obvious fault in the film’s depiction of passing can hardly be ignored. As you’re not meant to know that the lead character of Stain is in fact passing, and has been doing so for his entire life, the casting of Anthony Hopkins — who you will recall is white — is explained away as a necessary subterfuge. The alternative would have been to cast an unknown, light-skinned actor of African descent, and to have the character’s big reveal also apply in some degree to the actor. It’s justifiable in a sense, but it still leaves a bitter taste in the mouth in an age when black actors are frequently typecast and whitewashed out of juicier roles.

Passing, conversely, is the first film about the subject directed by, written by and starring women of African descent since Illusions in 1982. The tale these artists have crafted is one of careful intent, calibrated such that the release of the final scene lands like a gut punch. Last week the film was picked up out of Sundance by Netflix, which is likely the best distributor for a story like this. Though it likely won’t hit theaters or the streaming service for quite some time, Passing‘s look to the past is certainly worth the wait.