BITTERSWEET. By Colleen McCullough. Simon & Schuster. 352 pages. $26.

"Edda drew in a great breath, lifted herself and the chair a few inches and brought the left front leg down on the middle of the snake's head. ... The leg pierced its skull between the eyes and the snake, all seven feet of it, reared high into the air."

This dramatic scene takes place in the drawing room of the Latimer family in the town of Corunda in New South Wales, Australia, at the start of Colleen McCullough's new book, "Bittersweet," a romantic family saga.

From here we follow the lives of the main characters: the four Latimer sisters (two sets of twins): independent and self-willed Edda, self-centered and complaining Grace, capable and intelligent Tufts (Heather) and Kitty the beauty of the family.

The girls are getting ready to embark on an independent future, to become trained and registered nurses during the 1920s when women's best hope usually was a suitable marriage or perhaps a secretarial position. The sisters move to the grounds of Corunda Base Hospital, working under the watchful eye of frosty matron Gertrude Newdigate, "her head encased in what looked like a large white Egyptian headdress."

They adjust to the many rules and long hours as they perform duties in their stiffly starched uniforms.

Enter the men in their lives: neighbor Jack Thurlow, a man of the land who raises sheep and Arabian horses; Bear Olsen, a salesman and commercial traveler; and two doctors, Liam Finucan, a surgeon at the hospital in an unhappy marriage, and Charles Burdrum "a bantam rooster of a man" from England who is to be the new hospital superintendent.

The story traces the twins' lives through their successes, romances and heartbreaks; it is written well enough to keep us turning the pages, but somehow something is missing. The diverse cast of characters that McCullough has put together just does not engender sufficient sympathy. "Bittersweet" suffers in comparison to her hugely successful book, "The Thorn Birds."

Reviewer Frances Monaco is a writer in Charleston.