Dinah Lasker, who had briefly been a communist in her youth, agrees to name names to the House Un-American Activities Committee. She does it to save her husband Jake's career as a writer and director of Hollywood comedies. She does it to hold on to the Beverly Hills life she's provided for her two kids. In most books and films about the Hollywood blacklist era, Dinah would be cast as the villain. In "Cheat and Charmer," Elizabeth Frank's juicily melodramatic page-turner of a first novel, the informer turns out to be the most sympathetic character. Not because Dinah, or the author, approves of McCarthyism. It's that everyone else in this sprawling tale is far more accomplished than she in the arts of duplicity and selfishness. Dinah struggles with her conscience. Most of the others--including her loving but philandering husband, Jake --don't have one.

Calamitous events result from Dinah's testimony, but the blacklist isn't really what the novel is about. It's the catalyst for an exploration of family, marriage, sibling rivalry. One of the names Dinah offers up under threat is that of her sister, Veevi, a legendary beauty who's been living the expat life in Paris with her novelist husband, Mike Albrecht (a cross between James Jones and Peter Viertel). When Mike dumps Veevi for a younger French actress, the devastated beauty returns to Hollywood to live with Dinah and Jake, barely concealing her contempt for Dinah's bourgeois aspirations. Veevi regards her bohemian, European lifestyle as a form of moral superiority.

Frank, the daughter of writer-director Melvin ("A Touch of Class") Frank, and a Pulitzer Prize winner for her biography of poet Louise Bogan, has an intimate grasp of the social and political landscape of '50s Hollywood. (Her take on literary cafe society in Paris feels more secondhand.) She understands how those who've achieved huge success can misbehave with impunity, forgiven by their admirers but more so by themselves. This is not a cliched indictment of Hollywood: the "serious artist" Mike, who excoriates Dinah for ratting to the committee, is the biggest hypocrite of the lot.

There's a certain pulpy predictability to the betrayals, blackmails and bed-hoppings that keep this 539-page saga humming. And there's not much to savor in Frank's prose, which is merely functional: it's her insight into her many characters that impresses. "Cheat and Charmer" is at its best when it's deep inside the Lasker family dynamic. When Dinah makes her bargain with the HUAC Devil, she's dreaming the American dream that her family can live outside history. History, as usual, is not inclined to oblige.