Before Anatomy of a Fall gives us a body, we get a booming steel drum cover of 50 Cent’s “P.I.M.P.” It’s coming from upstairs, where Sandra’s (Sandra Hüller) husband is insulating the attic. But he’s playing the music loudly — possibly out of spite. Sandra is downstairs answering a grad student’s questions about her career as a successful novelist, speaking pretentiously, and predictably, about how reality informs her fiction. Samuel (Samuel Theis), the husband, is also a writer but has never been able to publish a book. Blasting horrible music is perhaps how he expresses that bitterness to his wife. An hour later, he’ll be found outside, head cracked open after tumbling from the third floor.

That’s the initial assumption at least. But we don’t see how Samuel died, and the police investigation suggests some inconsistencies with Sandra’s story. Was it an accident? Suicide? Or was it… murder?

In director Justine Triet’s third film, a darkly comic courtroom drama and winner of the Palme d’Or at the Cannes Film Festival this year, everyone wants to know if Sandra killed her husband. But the film suggests that this isn’t the only question we should be asking. Anatomy of a Fall is a crime story — but in its vision of the legal system, justice is a search less for the truth than the perception of it.

The film’s title carries a double meaning. There’s the literal fall of Samuel — his death investigated through the sometimes slapstick science of forensics as the police examine odd blood splatters and the defense goes as far as simulating the fatal plummet with a life-size dummy. And there is the figurative fall of Sandra as the circumstances of her life are picked apart after her indictment. The trial that follows is an act of humiliation. Her light infidelities become a reflection of her character. Her work — the fiction she writes — is called into question, all because she has admitted to drawing upon reality to inform her novels, as if this isn’t a rote opinion from any author.

But more painful are the excavations of her marriage, which has been strained for years under the pressure of money, ambition, and child-rearing. Pretty regular marital stuff, until it’s cross-examined. As Sandra explains to the jury, “Sometimes we fight together. Sometimes we fight alone. Sometimes we fight each other.” It’s the kind of broad sentiment that can apply to any relationship. Unfortunately, it doesn’t sound so great out loud when she takes the stand.

Hüller is remarkable at the center of a movie full of great performances, wavering between arrogance and vulnerability. She’s not unsympathetic, but we’re not exactly in her corner, either. One extraordinary scene, recounting a violent argument Sandra and Samuel had the day before the fall, takes the unpredictable direction of grounding itself in the mundane: a couple fighting about who has more time to themselves. (They are both writers, after all.) The film’s most dramatic moment also feels like its most realistic.

All of this plays out in front of Sandra’s 11-year-old son Daniel (Milo Machado Graner). Daniel suffered optic nerve damage after being hit by a motorcyclist at age four — on a day Samuel was supposed to pick him up from school but skipped out and sent a sitter. Though much of Daniel’s sight has healed, the wound never quite heals between Sandra and Samuel.

Anatomy of a Fall is most effective as courtroom theater. The punchy sparring is especially good from the prosecutor (Antoine Reinartz), equal parts catty and smug — a satisfying villain even in a movie where there aren’t really bad guys. But the trial also sharpens the film’s central idea: in the absence of understanding how something happens, we instead ask why.

Triet’s last film, Sibyl, had a similarly strong premise (also about a writer). A psychoanalyst decides to turn her attention back to her career as a novelist, but when a new patient’s messy life makes the perfect fodder for fiction — an actress has an unwanted pregnancy with a co-star, who is dating the movie’s director (Hüller, again) — Sibyl begins recording their sessions in secret. It’s juicy stuff, but the melodrama eventually consumes the characters, and despite several terrific performances, there’s little to take away from the film once all the crying, shouting, and hotel room trashing is over.

If Sibyl seemed to lose the thread of its excellent premise, Anatomy of a Fall certainly does not. In fact, its intense focus on its themes drives the film forward and through its final act. It’s a long movie — around 2.5 hours — but it moves swiftly, expertly paced and edited, and wraps with a clever ending that puts a lot of trust in young Machado Graner. (He totally lands it.)

Fall is clever, cutting, and nimble, a mystery that relies not on sleight of hand but on cruel honesty. What Sandra says at the beginning of the film — that reality informs fiction — is wrong. In fact, it’s the other way around. At one point, Sandra makes the case bluntly to her lawyer: “I did not kill him.”

He seems to get it, because he quickly replies, “That’s not the point.”