Jane Smiley's new novel is not for readers who blush easily.

Ten Days in the Hills (Knopf, $26) is saturated with sex: loving and satisfying sex, luxuriant and unabashed sex, romantic and silk-sheet sex, middle-aged and earnest sex, explicitly and richly described sex. Just about everything but married sex.

It's impossible to ignore the sex in Ten Days, because it's right there on the first page. And while it's not on the last page, it's on plenty of pages between.

Smiley will discuss her book tonight at the Central Library of the Free Library of Philadelphia. First-time novelist Patricia Marx is also scheduled to be on the program to talk about her book, Him Her Him Again the End of Him.

On a recent morning, Smiley talked by phone from her home in Carmel Valley, Calif., about her 12th fiction title.

She recalls, as she finishes her bowl of breakfast cereal, that she didn't hesitate a moment over writing all that sex into her book:

"I do remember thinking, 'OK, how am I going to do this?' and I do remember thinking to myself in exactly these words, 'Well, I don't exactly want to sexualize my novel, I want to novelize sex.' So, I wanted the story to just keep on going, through the sex and beyond."

The sex has certainly caught the attention of reviewers.

John Updike quoted at length from some of the racy passages in a favorable New Yorker review, and observed that "the sexual descriptions set a new mark for explicitness in a work of non-pornographic intent."

The New York Times' Michiko Kakutani referred disparagingly in her review to "pages and pages of R-rated (sometimes X-rated) accounts of . . . sexual shenanigans."

Some readers inevitably will be put off by the sex saturation. One sophisticated, non-prudish reader had enough after reading 50 pages of the galley. It's not as if she had never written about sex before, Smiley marvels, noting that she has twice been included in The Best American Erotica. The sex scenes in Ten Days, she adds, are "an enhancement rather than a departure, I would think."

In any event, they were probably an inevitability, given the nature of the book Smiley set out to write in January 2005: a Hollywood novel that would be a "remake" (Smiley's word) of Giovanni Boccaccio's 14th-century masterpiece, The Decameron.

Smiley, who won a Pulitzer Prize for her novel A Thousand Acres, had wanted to write a Hollywood novel since the late '90s. Her decision to steep it in sex was a reaction to the 1998 movie Meet Joe Black, which she thought offered an unrealistic view of love.

It's impossible to write about true love without writing about sex, she concluded.

After meeting Joe Black, Smiley met Giovanni Boccaccio when she read The Decameron in 2001 (appropriately enough, during the anthrax scare).

Boccaccio's work - memorably ribald, irreverent and hilarious, a compendium of coupling, cuckoldry and craftiness - reinforced her feelings about the link between love and sex.

In The Decameron, 10 young residents of Florence, Italy - seven women and three men - take refuge from the plague in the nearby hills. They pass the time there by telling stories over the course of 10 days - 100 in all. ("Merry tales," Boccaccio called them.)

Smiley says she loved The Decameron's narrative diversity, which she thought would work well for her Hollywood book. She also loved the way Boccaccio "explores the differing kinds of sexuality of a lot of people in his stories."

But Smiley also knew she would have to do a little adapting to build Ten Days from the Decameron blueprint.

"I realized that a modern novel actually had to be a novel," she says. "It had to have an overarching story, and the characters had to be transformed by their 10 days. . . . I felt I had to be little flexible, but [the characters in Ten Days] do tell all kinds of narrative."

In Smiley's remake, 10 people come together for 10 days in March 2003 in Pacific Palisades, high above Los Angeles.

The Ten Days ensemble includes a director, his ex-wife (a movie star), his ex-wife's mother, his unemployed adult daughter, his girlfriend (a self-help author), his agent, his girlfriend's son (a college student), his ex-wife's lover (a Buddhist-like therapist who may be a charlatan), his childhood friend (an ardent supporter of the Iraq war) and a gallery owner who is his ex-mother-in-law's best friend.

It didn't take long to assemble her cast, Smiley said. The first two were Max, the director, and Elena, the girlfriend.

Smiley, 57, made Max and Elena fiftysomethings, which made it easy to add their grown children to the group.

The other characters "just sort of popped up," she said. "There was no effort in trying to come up with them."

The gathering begins as a serendipitous house party at the multilevel mountainside abode of the director, Max, but it quickly turns into a temporary refuge from the world below, where the United States has just invaded Iraq.

"What do you want to do today?" Max asks Elena.

"Hide out from the war," she replies.

"I think the war was very shocking for everyone," Smiley says. Her characters are "adjusting themselves to the new world order, which would happen to be a warring one."

Not much happens in Ten Days, and Smiley knows that her Hollywood book probably will never be a Hollywood movie.

"It doesn't have enough action," she says. "What are they going to talk about? It's My Dinner With Andre [multiplied] by 10."

Some ultra-rich Russians try to get Max to direct a remake of the 1962 movie Taras Bulba. Max's agent, Stoney Whipple, pushes the project as a way to get Max, whose career has been in eclipse since winning a best-screenplay Oscar in the '70s, back into the California sunshine.

Other characters try to sort out their lives, with varying degrees of success. Open the book randomly to any page, and you'll usually find somebody talking or making love - often at the same time.

(Ten Days is a very talky book, to the critics' dismay. The characters discourse more than they converse. Large chunks of dialogue resemble nothing so much as eloquent, finely crafted lectures.) Whatever the critics might say and whether any readers may be put off by the sex, Smiley says she had "a wonderful time" writing Ten Days.

And she's happy with what she's done.

"I love reading funny novels and I love writing funny novels," she says. "This novel is funny, even though it takes place during a pretty serious period and is about serious things."

Contact staff writer Michael D. Schaffer at 215-854-2537 or mschaffer@phillynews.com.