Book REVIEW / NOVEL : Real Life, Romance and Family Feuding : SHADOW RANCH by Jo-Ann Mapson HarperCollins $24, 375 pages

“Shadow Ranch” is as romantic as any drugstore bustier-buster, but it masks its intentions with tragic events, a comic style, a cast of realistically dysfunctional characters and an acutely detailed Southern California background.

Like Jo-Ann Mapson’s first two novels, “Hank & Chloe” and “Blue Rodeo,” this is a love story for grown-ups, propelled by the attraction between improbable lovers.

They don’t get much more improbable than rich, crusty, 80-year-old Charles Russell “Bop” Carpenter II and Earlynn Sommers, the Texas ex-stripper he sees baring her past on the “Sally Jessy Raphael” show as he broods in front of the TV in his Frank Lloyd Wright mansion in Huntington Harbour.

Bop--indeed, the whole Carpenter clan--has been in a funk since his 4-year-old great-grandson, Spencer, died of an inherited heart defect, the same malady that killed Bop’s son, Chuck, at 37.

Grief has unhinged Spencer’s mother, Lainie. She so deeply resents Bop’s having briefly committed her to a mental hospital that she refuses to let him help pay her crushing medical bills. Her odd behavior--mostly compulsive cooking--threatens her marriage with Nick.

She is terrified of passing on the “Carpenter heart” to any other offspring, and haunted by the thought that Spencer has “left the Earth uncertain and afraid.”

Lainie’s brother, Russell, has rejected his grandfather Bop’s workaholic ways with a vengeance, surfing, collecting guitars and avoiding marriage.

“We spend all this time groping our way past the gaping hole Spencer left in our lives,” Nick tells Russell. “We have to start trying to sew the bastard back together.”

Add in neurotic dogs, untamed horses, an environmental controversy and--yes--a Los Angeles Times reporter who used to be Bop’s rival in love and is now bent on blackmailing him, and the mess seems beyond repair.

Salvation comes from two unexpected sources. One is Earlynn, who fan-danced under the stage name Early Summer and whose hardscrabble life has endowed her with a sweet but gritty wisdom. The other is Bop’s realization that he was happier growing lemons on Shadow Ranch in San Diego County with the first of his four wives than he has been in his later life as a tycoon.

“One of the fundamental problems to be found with California in the 1990s,” he grumps, is that “everyone ran around trying to act like old money, when the green ink on their bills hadn’t even dried. . . . True old money in the state was unrecognizable, mostly because it looked, smelled and tasted a lot like dirt. . . . Land like Shadow”--which Bop considers selling his prestigious home to repurchase.

Mapson, a Costa Mesa resident, has the background to make this appeal to traditional California values persuasive. She takes characters whom it would be easy to satirize or villainize and treats them all (except for the reporter) with sympathy. We understand each of them and understand, too, why they resent one another. That’s a neat trick for any novelist to pull off, and Mapson does it with ease.

“Shadow Ranch” is full of expertise about horses, guitars, and architecture; full of well-drawn, humorous yet edgy scenes between feuding generations and Mapson’s elderly lovers. It’s like a thrill ride though the recognizable and often unpleasant territory of real life before the romance kicks in.