As the series progresses, the structural gimmick begins to make the murder feel extraneous, almost as though it were a red herring—and the most delicious thing about the finale is that, in a way, we learn, it is. The great revelation of “Big Little Lies” is not the identity of the murder victim (it’s Perry, Celeste’s abusive husband, luridly played by Alexander Skarsgård), or the identity of the killer (that would be Bonnie, the young bohemian married to Madeline’s ex-husband, and played by Zoë Kravitz; she sees Perry beating Celeste and pushes him over a drop-off—in the book, Bonnie has her own history of being abused). The finale was set up to answer a different question. The women have been revealing their secrets in pieces throughout the series, and Jane’s secret is that her son, Ziggy, was conceived in a violent rape by a man she had just met. When, on the night of the fund-raiser, Perry approaches Celeste in a predatory fever, Jane, who has not previously been introduced to Celeste’s husband, suddenly recognizes his look: Perry is the man who picked her up, gave her a fake name, and assaulted her in a motel room. He has raped both of them, and fathered their sons.

Part of what has made “Big Little Lies” stand out amid the ever-growing crowd of interesting TV shows is its utterly natural rendering of violence as an ordinary part of women’s lives. (My colleague Emily Nussbaum described the show in her review as “a reflection on trauma.”) The show understands that minor social transactions between women can express the nuances of violence with a unique specificity and a nauseating subtlety. Jean Marc-Vallée, the director, roams these sun-drenched, luscious settings with a handheld camera and a sense of unease. In the finale, just before the climax, as a ballad drifts in from the lantern-lit party, fifteen remarkable seconds pass. One of Jane’s P.T.S.D. flashbacks has merged with the present, confirming Perry’s identity; her face becomes a mask of fear. Madeline looks at her, follows her gaze to Perry, and then looks back at Jane, altered—she’s figured it out. Madeline catches Celeste’s eye and turns it toward Jane, who nods almost imperceptibly. The show’s twist has been communicated wordlessly among all three of them. Witnessing this, Perry panics, and lunges forward to bludgeon his wife.

It’s an electric sequence. Witherspoon, as Madeline, was the immediate draw of “Big Little Lies,” with her mutinous Tracy Flick charm resurrected and blazing. But Kidman, as Celeste, emerged as the real showstopper. She has the most ambitious narrative arc in the series, the widest gap between appearance and truth. To friends and neighbors, her relationship with Perry looks dreamy and lustful; it’s actually a maelstrom of codependency and marital rape. (Male critics have written differently about “Big Little Lies” than women, by and large—at the Times, Mike Hale noted that Celeste was an abuse victim but then compared her relationship with Perry to “Fifty Shades of Grey.”) Celeste responds to abuse in a manner that feels painfully realistic. She tries to take ownership of her situation by hitting him back; she tries to find pleasure in it, fitting her lust around his blows. She articulates a neat narrative to Madeline; then a messier one to a therapist (Robin Weigert), with Perry present; then she tells an increasingly honest story as she returns to the therapist alone. By the final episode, Celeste has rented and furnished an apartment; a brutal and unambiguous beating has made her ready to leave with her twin sons. But Perry sees a message from the property manager on Celeste’s phone just before they leave for the fund-raiser, and, watching husband and wife get in their car, leaving the kids behind with a babysitter, you fear for her life.

By then, the show’s secondary mystery has been solved. There’s a bad seed in Otter Bay’s first-grade classroom: some kid has been bullying a girl named Amabella, who, in the first episode, identifies Jane’s son Ziggy as her attacker. Ziggy, though, maintains his innocence, and, in the finale, he reluctantly tells Jane that the kid who has been choking and biting Amabella is Max—one of Celeste’s twins. On the day of the fund-raiser, Jane breaks the news to Celeste as gently as she can. “I definitely considered the fact that he could be lying just to protect himself,” Jane says, referring to Ziggy. “And I had to face the fact that violence could be in his DNA, given who his dad is.” Celeste reels. She’s been telling herself that the twins don’t know about the abuse, but we know this is wishful thinking: the finale opens with a shot of an air vent in Celeste’s basement, through which the boys, playing with video games and toy guns, can hear her scream. Their world is already a miniature version of Celeste’s, beautiful and violent. “They grow out of it,” Jane says to Celeste about bullying kids. “Sometimes they don’t,” Celeste replies.’