It is Valentine's Day in San Francisco and Frank Curtis -- "a journalist who lacked that blood taste in his mouth, too much preoccupied with his orphaned youth, his notion that a good woman might make him vivid to himself" -- is at a party in the Old Spaghetti Factory & Cafe. He is minding his own business when into his line of vision wanders a miracle named Suki Read:

"The world is blessedly full of coincidences and happy accidents of nature. Flashing narrow white thigh beneath slit folds of slithering cloth, flashing small pink and white breasts in a silken blouse with an extra button undone, showing tips of teeny-tiny white teeth as her mouth came open with laughter, Suki was a small bright package of delights. She smelled spicy and good; it was more cloves than sweet; she moved around a lot. She was very active, awfully nice -- that smile urgent and changing. How sure she was. Bright, even in theology. An innovator in contemporary religious thought. She knew she could arrive with nobody and go home with almost everybody."

This time she goes home with Frank Curtis, whose life as a consequence will never be the same. Suki, soon to turn 40, is what men dream of when they're California dreamin', a woman who "wanted to have a surprise for everyone and she wanted it to be Suki," who "had obligations to keep life a festival, as it must be." At the moment she is living with a man, but the night with Frank is okay because "we have a faithful relationship of total fidelity within a radius of two hundred miles" and he, at the moment, is away on business in Chicago.

But as Frank soon learns, "total fidelity" is a concept utterly beyond Suki's comprehension. In the northern California culture of promiscuity, she is the reigning champion, the ultimate sure thing. There's a little bit of something for everybody in Suki, and she passes it around to anyone who passes her fancy. Into the bargain she's very liberated, so Peter, her adolescent son -- she is divorced, of course -- gets to meet all the men who troop through her brie-and-ferns household: "Since he was the most important thing in the world to her, she owed him the same respect she gave herself. She tried not to interfere with his raising of himself. Her theory was part of the general deal she made -- non-interfering consistency."

It's all so California you can scarcely believe it, and Herbert Gold does a wittily devastating job of exposing its every vanity and frivolity. He also -- and this is the novel's real point -- penetrates beneath the glittery surface to reveal that the promiscuity in which Suki and her culture delight places intolerable burdens on the slender shoulders of her son. "A Girl of Forty" is in many places an exceedingly funny novel, but its dark side is what gives it weight: the desperate course Peter chooses to follow in order to cry out against the lovelessness with which his mother so freely makes love.

Peter is handsome, spoiled, manipulative: "The look on his face was boyish, sulky, jokey, ingratiating, that complex talent of the teenager in California or anyplace, the one with his own room, stereo, tape deck, video equipment, wheels, secrets, power, a history of getting his own way but not getting what he wanted." He is also, in the words of a policeman who becomes involved with Frank and Suki, "centerfold material in Horror magazine."

Denied genuinely maternal attentions by Suki -- who thinks of him not as a son but as a companion -- and having no strong male in his life, he strikes out insanely against Frank, the one man who offers him something approximating paternal interest and affection.

"A Girl of Forty" is the best novel Gold has written in a long time: tough, funny, worldly, smart. Its one flaw is that Suki, who is in love with nobody except herself, is allowed to get off too lightly; after exploring every nook and cranny of her empty loveliness, Gold cannot let her go and grants her an absolution that circumstances simply do not warrant. But otherwise he does not falter, painting a portrait of the self-indulgent California culture that is very much in the tradition of Nathanael West; he has a sharp eye for the revealing detail, yet never suffocates his story in minutiae or lapses into mere parody. "A Girl of Forty" is fun; it is also chilling.