The actress Myrna Loy, best known for her enchanting chemistry with William Powell in the "Thin Man" movies of the '30s and '40s, died in 1993 at the age of 88. Though her life was remarkable, both from her years in early Hollywood and her personal history of political activism, it took nearly 20 years after her death for a biography of her to be published — because, it seems, she didn't want one.

"She was such a private person," said Emily W. Leider, author of the biography "Myrna Loy: The Only Good Girl in Hollywood" (University of California Press), in an interview last week. Though Loy left an archive of her papers at Boston University, she meticulously removed from it a number of personal letters, and left no diary.

"Anything truly intimate or revealing, she did not want the world to know," Leider said. Loy played the perfect wife on-screen, but her personal life was less sunny: four marriages, four divorces, and, to her great sadness, no children.

Leider will be in town Saturday for a presentation at the Grand Illusion titled "Thoroughly Modern Myrna," an examination of how Loy's look evolved from the silent films of the 1920s (where she was frequently cast as a mysterious exotic) to the '30s, in which she became the witty, all-American fantasy wife. Film clips and stills will accompany the talk, and Leider will sign copies of her book following it.

Loy, born Myrna Williams in Helena, Mont., in 1905, was a breath-of-fresh-air presence on screen: her face with its delicate, almost feline features always exquisite; her touch with comedy always perfectly light and utterly winning. Watch her Nora Charles in her first scene in "The Thin Man," as she enters a bar to meet her husband, Nick, but trips and falls while being dragged by their enthusiastic terrier, Asta. Apologizing for the commotion, Nick explains to a hotel employee that "it's my dog, and my wife." Nora, barely looking up from her makeup compact, observes pertly, "Well, you might have put me first on the billing"; her delivery breezy as a spring afternoon.

Loy never won or was nominated for an Academy Award (though she was given an honorary Oscar in 1991), a shocking oversight that may have its roots in the actress's liberal politics. (Some studio heads, Leider said, "had it in for her.") But her career encompassed nearly 60 years of filmmaking, from the silent era to the TV age; and her leading men included the likes of Powell, Cary Grant, Clark Gable, Spencer Tracy, Tyrone Power, Montgomery Clift, Henry Fonda and (playing her son) Paul Newman.

Leider, previously a biographer of Mae West and Rudolph Valentino, became drawn to Loy through her research into Valentino, who helped Loy (then a dancer at Grauman's Egyptian Theatre in Hollywood) get her first screen test in 1925. At first intrigued by the actress's on-screen charm, Leider gradually found herself drawn to Loy as a person.

After spending years researching, reading and interviewing the few people still living who knew Loy well (most notably her stepson), and watching films and clips, "she just got more and more admirable in my eyes," Leider said. "I think she had such solid values. She always saw beyond Hollywood, and that is rare among stars. It's maybe one reason that she didn't remain a big star." The screwball comedies in which Loy excelled eventually went out of fashion; the perfect wife on screen found fewer and fewer roles.

More important to Loy than Hollywood fame was the idea of making a difference: She worked on presidential campaigns, participated busily in war-relief campaigns during World War II, became an activist for the United Nations, and didn't hesitate to speak her mind — to the extent that her films were banned in Germany in 1939, as she was considered an enemy of Hitler. She didn't mind a bit. "Why should I be entertaining the Third Reich?" Loy later wrote in her autobiography, "Being and Becoming."

And Loy adored Eleanor Roosevelt, always keeping a photo of the former first lady in her apartment. "Eleanor was her ideal as a human being," said Leider.

Though Loy's careful privacy sometimes brought frustration to her biographer, Leider said that getting to know her through researching the book was a joy. "She was a wonderful companion," said Leider, of the six-year saga of writing the biography. "I really miss her."

Moira Macdonald:

206-464-2725 or mmacdonald@seattletimes.com