Helena Bonham Carter stars in this three-part “Masterpiece” biographical drama about Noele Gordon, a pioneer of British television. “Stars in” might be understating it: She’s in nearly every scene, trembling, laughing, sobbing, scolding, scheming, singing “Rose’s Turn.” Her chin tilt is the very axis on which the show spins.

Gordon, known as Nolly, was the first woman on color television, and she was a presenter, an early TV executive and eventually the lead of the long-running, low-budget soap opera “Crossroads.” “Nolly,” which premieres Sunday at 9 p.m. Eastern on PBS, focuses its story on her firing from “Crossroads” after nearly 20 years as its star and creative anchor. She’s blindsided, as are the show’s millions of fans. She’s also heartbroken: The end of her character and the end of her self are practically one and the same. She pleads with a producer not to kill her character off. “It’s not a real death,” he snaps. “But still,” she says. It is.

“Nolly” makes good use of that overlap between on-camera and off-camera life, how people — women especially — are yanked around or cast out within their own lives. Nolly delivers multiple righteous monologues standing up for her maligned show, for soaps in general, for women’s interests, for those who are overlooked and rejected, especially her.

Created and written by Russell T Davies and directed by Peter Hoar, “Nolly” is mercifully light on its feet. Corrective, finally-getting-their-due sagas can sometimes feel like cultural penance, a televised hair shirt to abrade us for our blind spots. “Nolly,” though, is fun and savvy, and its tone lands right between “Slings & Arrows” and “Hacks” — smart, cutting, with characters (and characters playing characters) who are simultaneously ridiculous and brilliant.