BOOK REVIEW / FICTION : Unlikely Pair Writes the Wrongs in Life : ISABEL’S BED, A Novel <i> by Elinor Lipman</i> , Pocket Books, $20, 387 pages

You can keep your revenge tragedies; for my money there’s nothing more delectable than a good revenge comedy.

The modern standard has been set by Fay Weldon’s “The Life and Loves of a She-Devil,” but in “Isabel’s Bed” Elinor Lipman has written something at least in the same league: a winsome, even sweet tale of women spurned and self-redeemed. The novel is populated by intermittently angry women, and it will surprise no one that the objects of their revenge are the men in their lives. To modify an old joke: Men--you can’t live with ‘em, and you can’t shoot ‘em (usually) with impunity.

Harriet Mahoney, the Manhattan secretary and unpublished writer who narrates this novel, has been dumped by her boyfriend. She’s depressed and hurt and indignant, and rightly so: Harriet is 41, has put a dozen years into her relationship with Kenny the bagel maker, and he has already moved on to marry--on Valentine’s Day no less--the younger woman who caused their break-up. Harriet needs to change her life and knows it, and for the first time buys an issue of the New York Review of Books, seeking . . . something.

Her prayers are answered: She finds a classified ad in which the owner of a Cape Cod retreat offers room and board in exchange for a writer’s services. Harriet is selected from a sophisticated group of applicants: “No prima donnas,” says Isabel, the ad-taker, on phoning Harriet with the good news.

Harriet, upon arriving in Truro, is surprised to discover that she will be sharing not a modest shingled summer cottage but a modern, million-dollar, award-winning show home. That’s not her biggest surprise, however: Her landlady / housemate turns out to be the beautiful, blond, centerfold-bodied Isabel Krug, perhaps the most notorious Other Woman of the day.

Harriet has apparently missed the 1980s media infotainment wave, but Isabel happily provides the particulars: Isabel was in bed with millionaire businessman Guy VanVleet when his wife burst in and shot him through the heart. The wife, Nan, was found not guilty by reason of temporary insanity, and Isabel, for her part, became a pop-culture icon, like Claus von Bulow or Amy Fisher, infamous enough to have publishers and agents sniffing around for a tell-all autobiography. And that, of course, is where Harriet comes in.

Harriet hadn’t given much thought to the work expected of her, and certainly had not anticipated collaboration with a celebrity adulteress and eyewitness to murder. She quickly falls into the flow of things, though, for Isabel proves charming, sympathetic to Harriet’s problems with men and encouraging of her hoped-for literary career.

Isabel is not a task-master, either; she is thrilled that Harriet can cook, and in no great hurry to put her story to paper. She gradually reveals herself, however, and proves much more interesting than Harriet initially assumed. Isabel is married to a now-disgraced photo-realist painter, a much older man with a twisted past; she greatly enjoys sex and general nakedness, and became involved with VanVleet for fun more than love; she tells hilarious stories; plays life by her own rules, and sincerely calls everyone with the slightest bit of talent “a genius.”

Late in the novel Harriet describes herself as “an oversized Campfire Girl” and Isabel as a “ femme fatale .” It’s an accurate description, so far as it goes, but by that point the identities of the two women have evolved; Isabel has proved to be a savvy and talented woman, and Harriet more than a bumbling ne’er-do-well.

Lipman writes in the publicity material accompanying “Isabel’s Bed” that the novel germinated when she learned that Pocket Books, her own publisher, had paid Ivana Trump $1 million for a ghost-written, fictionalized version of her life. Lipman, upon asking her agent why she couldn’t be Ivana’s ghostwriter, was told she probably didn’t have the right clothes, literally or metaphorically--but the agent later added that she’d love to see Lipman write a novel based on similar collaboration. The agent’s idea, as “Isabel’s Bed” makes plain, was inspired, and there’s a certain justice in seeing Ivana Trump--who has contributed, like countless other self-promoting celebrities, so much to tabloid culture--inadvertently lending her life to literary culture.