BOOK REVIEW A Gothic Tale Gets an Upscale Update : KEEPER OF THE LIGHT <i> by Diane Chamberlain</i> ; HarperCollins $22; 435 pages

Portentous and melodramatic, “Keeper of the Light” is our old friend the Gothic romance, updated and up-scaled. Instead of an impecunious governess lured to an isolated heath, Olivia Simon is a doctor practicing on North Carolina’s Outer Banks, persuaded to move there by her husband Paul Macelli, a poet doing occasional features for the local Gazette while awaiting inspiration for his masterpiece.

Rusticating on the Outer Banks, Olivia is working in the emergency room of the small hospital, missing the excitement of her responsible job at Washington General and wondering why her marriage seems to be disintegrating despite her amenability to Paul’s whims.

Olivia is on duty Christmas Day, when Annie O’Neill is brought in with a bullet wound to the chest. The victim is the town’s most beloved citizen--a beautiful and talented Lady Bountiful, known for her myriad good works. Annie had actually been serving roast turkey in a women’s shelter when the gunman roared in to find his estranged wife and shot Annie instead. The wound is mortal, and though Olivia performs a heroic open-heart operation, Annie O’Neill dies.

One would naturally expect Annie’s husband and children to be distraught, but Olivia’s husband, Paul, is equally grief-stricken. As far as Olivia knows, he had met Annie only recently, when he’d interviewed her for the paper. She’d enchanted him as she charmed everyone, but in his case, enchantment meant infatuation.

Not even trying to console Olivia, devastated at her failure to save the patient, Paul storms out of the house, leaving his wife alone to face the hostility of her colleagues and the anguish of the entire town. Inevitably, there’s an inquiry, blaming the new young doctor for acting irresponsibly and impulsively.

Apparently feeling that she’s deprived the area of its greatest asset, Olivia does her best to fill the void left by Annie’s demise. She seeks out the studio where Annie produced her stained glass fantasies and studies the craft after her long hours at the clinic.

As if working in an emergency room were not humanitarian enough, Simon involves herself in the same voluntary activities that occupied Annie, naively hoping that turning herself into a clone of the dead woman might rekindle Paul’s love.

He remains unimpressed, however, determined to proceed with a divorce. “It’s my fault,” she insists. . . . “I’d do anything if you’d come back. I’d work as a waitress. I’d shell shrimp. Shuck oysters. Just weekdays. No evenings or weekends.” This and other similar passages suggest that “Keeper of the Light” might be the ultimate backlash novel, crammed with hints that women who succeed at demanding professions are unlovable.

There’s a lot of space to fill here, and more than enough back story to ensure the novel a secure place in the romantic pantheon. Annie O’Neill, her husband, Alec; Paul Macelli and Olivia Simon all seem to have remarkably long histories for people still in their 30s.

A grass-roots movement to save the endangered lighthouse supplies both a central symbol and a trendy environmental subplot. Although the dialogue is merely serviceable and the characters archetypal, Chamberlain has a fine Gothic touch with plot and is adroit at integrating the many flashbacks into the narrative proper.

A spirited nonagenarian lighthouse keeper not only provides some authentic local lore but comes as a welcome contrast to the moony principals; Mary Poor, in fact, may be the only thoroughly modern woman of the lot.

Readers who found Annie O’Neill much too good to be true will be agreeably surprised to find themselves right, though they may continue to wonder why Olivia Simon was so slow to come to the same conclusions. But then, Annie O’Neill’s bereaved husband was gulled too.

Next: Carolyn See reviews: “The Seventh Stone” by Nancy Freedman (Dutton).