From March 1965 until January 1966, New York City was beguiled by an unexpected "it" couple. Andy Warhol — effete, strange-looking with his pallid skin and silver wig — was emerging as the principal practitioner of Pop Art. Edie Sedgwick — waiflike, modern with her pixie haircut and hoop earrings — was described as a debutante, heiress and member of the Boston Brahmins (none of which was actually true).

During their time together in the spotlight, which started in earnest when they appeared at a preview of "Three Centuries of American Painting" at the Metropolitan Museum of Art and received more press attention than fellow attendee and first lady Lady Bird Johnson, they dominated the Manhattan social scene. As Merv Griffin said of them when they appeared on his television show, "No party in New York is considered a success unless they are there."

Although the pair made for glamorous pictures, their fame was based on more than media coverage. During those 10 months, Edie was an integral part of the experimental films Warhol was making. His films were often little more than unedited reproductions of everyday life, such as a person sleeping or people kissing, but those featuring Edie, particularly "Poor Little Rich Girl," were real-life portraits of a beautiful and engaging subject. As Warhol later wrote, "The fascination I experienced was probably very close to a certain kind of love."

Their collaboration is the core of "As It Turns Out: Thinking About Edie and Andy," by Alice Sedgwick Wohl, Edie's older sister. The book is a family memoir with Edie as a primary focus. Unflinching in its honesty, Wohl's memoir provides a disquieting glimpse into one family in America's privileged class, a family made worthy of examination because one of its members — whose presence lives on luminously in her films — remains a source of fascination more than 50 years after her death.

Edie's parents, Alice de Forest and Francis ("Fuzzy") Sedgwick, were warned by a psychiatrist not to have children. They had eight. Edie was the penultimate. By the time she was born, the family had left a mansion in Cold Spring Harbor on Long Island for a ranch near Santa Barbara, Calif. When oil was discovered there, Fuzzy moved his brood to a larger ranch, Rancho La Laguna de San Francisco, where Edie spent her formative years. Her main activity was horseback riding.

As for Edie's mother, Wohl declares, "I never saw my mother lift a finger except to saddle her horse." She eschewed both housework and child-rearing. The father, a member of no fewer than seven private clubs, was an unapologetic racist who made sexual advances toward his daughters. "When Edie got to New York," Wohl writes, "she told everybody she had been subjected to Fuzzy's sexual advances from the age of seven."

One day when Edie walked in on her father having sex with "a beautiful young wife we all knew," he assaulted her and "called the doctor and said she was crazy." Edie told her mother what happened, but, according to Wohl, "Mummy wouldn't believe her ... and after that she was kept in a darkened room half-drugged all the time."

It's not surprising that during her teenage years and early 20s, Edie suffered from bulimia, aborted an unwanted pregnancy (then illegal), and served stints at Silver Hill, a psychiatric hospital in New Canaan, Conn., and "the modern incarnation of the old Bloomingdale Insane Asylum" in White Plains, N.Y., where she received electroshock therapy treatments.

So, Edie was anything but an uncomplicated young woman when she was introduced to Warhol on March 26, 1965, at a party hosted by movie producer Lester Persky at his Central Park South penthouse. Warhol was smitten — "Ooooh, she's so bee-you-ti-ful," he cooed — and invited her to the Factory, his studio. Unfazed by his celebrity — Edie was dating Bob Dylan — she went the next day, and the pair began a collaboration that produced some of Warhol's most memorable films, among them "Vinyl," "Poor Little Rich Girl," "Restaurant," "Kitchen" and "Afternoon."

One fact about "Afternoon" "makes me sad," Wohl writes, explaining that "the third reel would have been the opening segment of 'Chelsea Girls,' the most successful of all Warhol's movies, only Edie had it taken out." Under contract with Dylan's agent, Edie believed that she was headed for Hollywood, so she wanted to reduce her participation in Warhol films. That explains why, going forward, she was willing to be a character in Warhol's "a: a novel" — a book gleaned from events in the lives of various Warholites as recorded on 12 cassette tapes — but appeared in few films. The best was "Outer and Inner Space," which, Wohl observes, "is a very great work of art, and it kills me that Edie had no idea what it meant to be its subject."

The zenith of the Warhol-Sedgwick alliance came on Oct. 8, 1965, the night they attended the opening of curator Sam Green's Warhol retrospective in Philadelphia. A room that held 400 was descended upon by 4,000 excited fans eager to catch a glimpse of the couple. Unbeknown to Edie and others present, Wohl writes, "not even Andy could have sensed it — this was ... the absolute high point of her life and the apotheosis of Edie Sedgwick."

The collaboration ended in late January 1966 after a dinner at the Ginger Man in Manhattan. As Wohl describes the scene, Edie complained to Warhol, with everyone at the table watching, that he "wouldn't let her get close to him, and suddenly she said she didn't want him showing his films of her anymore because they made her look ridiculous." Soon Dylan arrived, Edie left with him, and Warhol had little to do with her again.

Edie's dream of a Hollywood career never materialized, and on Nov. 16, 1971, she died of a barbiturates overdose in California. What remains, Wohl observes in her sensitive, elegantly written memoir, is the work, the films themselves, which represent "the era of the image, which was just coming into being."

She adds, "Andy anticipated it." As, perhaps, in her own way, did Edie.

Paul Alexander has published eight books, including "Death and Disaster: The Rise of the Warhol Empire and the Race for Andy's Millions." He teaches at Hunter College.

As It Turns Out: Thinking About Edie and Andy

By: Alice Sedgwick Wohl.

Publisher: Farrar, Straus and Giroux. 272 pages, $28.