The particular horror that Dee Dee represents—the fundamental corruption of the maternal imperative to provide care—is magnified in The Act by stylistic choices. This is body horror by way of Walt Disney, a ghoulish fantasia of princess gowns, stuffed animals, prescription drugs, and physical harm. King’s Gypsy speaks in an unnervingly high-pitched voice (much like the real Gypsy), and is dressed by her mother in doll-like outfits: soft pink sweat suits, floral pinafores with Peter Pan collars. In one of the first scenes in the show, Arquette’s Dee Dee shaves her daughter’s head with tenderness. “I wonder what it would be like if it grew out,” Gypsy says, wistfully. A few scenes later, illustrating the absurdity of Dee Dee’s insistence that Gypsy’s hair won’t grow, the 5 o’clock shadow is already visible on her scalp.

The Act, like most superior true-crime stories, isn’t merely interested in re-creating what happened. It delves into the texture of Dee Dee and Gypsy’s life together: the details of their lies, the physical brutality Gypsy endures by way of unnecessary procedures, the question of how so many doctors could have been compelled to believe Dee Dee. The relationship between the two women is the show’s most fascinating element, and it relies upon the extraordinary performance of its two stars. Arquette could easily go full Mommie Dearest with Dee Dee, leaning into the character’s monstrousness. Instead, she uses restraint, playing Dee Dee as a woman whose worst behaviors are governed by fear. They’re also rewarded by the people around her. Gypsy and Dee Dee are “like royalty” at a particular medical center, a doctor says in one scene. The sicker Gypsy appears to be, the more kindness she and her mother receive.

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King, in many ways, has an even more demanding role, in that she has to convey Gypsy’s journey from victim to willing participant to a woman who sees murder as her only means of escape. In the second episode, the show makes clear how much she’s being forced to endure: Gypsy has taken to sneaking sugar late at night, her first act of rebellion against her mother, who insists she’s allergic to it. But her teeth begin to rot, and her mother takes Gypsy to the dentist. Before Gypsy begins to realize what’s happening, the buzz of the dentist’s drill amplifies. In the next scene, Gypsy’s mouth is horrifically bruised, and her teeth have been reduced to stumps. King makes Gypsy’s shock and humiliation palpable. Arquette’s Dee Dee, by contrast, is unnervingly calm, as if she’s been soothed by the process that has disfigured and traumatized her daughter.

Given that so much in Dee Dee and Gypsy’s relationship is unsaid, both actors powerfully communicate the subtext of their dynamic. The imagery The Act employs to build tension isn’t remotely subtle (red paint dripping down a wall, Dee Dee restraining her daughter with ribbons whose blue satin matches her Cinderella dress), but it works, thanks mostly to the sharpness of the performances. The only cost of the show’s heightened focus on its core two characters is that other cast members sometimes feel like an afterthought. Sevigny’s Mel has very little to do beyond providing a contrast with Dee Dee. A doctor played by Poorna Jagannathan, who is immediately suspicious of Dee Dee, is an intriguing possible antagonist, but the reality of the story means that she’s thwarted before she can fulfill her potential.