As one book closes, what comes next?

At long, long last, A.S. Byatt had done it. The 66-year-old writer had jotted down the final word in the last book of her four-part epic on a Yorkshire family that had lived in her head for 40 years. On that afternoon, in London, she put down her pen (yes, she writes her manuscripts in longhand, in a notebook with fine lines) and flipped on a camera.

For nearly three years, as part of a TV documentary film project, a camera had recorded Byatt’s thoughts during the writing of her latest novel, “A Whistling Woman” (Knopf). Byatt, the author of rich literary fiction including the novels “Angels and Insects” and the Booker Prize-winning “Possession,” works at a desk heaped with books, near a window that overlooks a garden visited by herons, geese and jays. The camera was to capture key moments, such as Byatt’s last day of work on what a critic in the Spectator magazine in Britain has called “one of the grandest and most ambitious fictional projects anyone has undertaken since the war.”

She stared at the camera in her attic, which doubles as an office and has a bright light to help her through the winter blues, or, technically, seasonal affective disorder. (Byatt spends part of the year in the South of France.) She looked into the lens and said, “ ‘Honestly, I’m so tired I don’t feel anything,’ ” the author recounted at tea recently at a Los Angeles hotel. “I would say something if there was anything to say, but I just felt completely exhausted.” The documentary, called “Scribbling,” is expected to air in Britain on BBC2 in the next few months.

Meanwhile, halfway through a two-week U.S. book tour, Byatt still sounded tired after a drive from San Diego for an appearance and a radio interview in Santa Monica. She didn’t want her picture taken; her publicist specified that Byatt would answer no personal questions. In a gray turtleneck, with her short salt-and-pepper hair, she looked just the way she does in her unsmiling book jacket photo.

Antonia Susan Byatt, known as “Dame Antonia” since she was made a dame of the British Empire in 1999, is a no-nonsense sort. But when talk turned to anything other than “A Whistling Woman” -- how she likes to watch Serena Williams and other tennis players on TV, how she rarely has tea and scones at home -- Byatt brightened and even allowed a hint of her diabolical side to emerge. She talked with glee about the cover for her upcoming book of short stories, describing the design as “very beautiful and slightly creepy.” One of the stories is based on an eclectic library of medical history run by the Wellcome Trust in London. The library’s collection is filled, Byatt explained happily, with an “endless sort of artificial limbs and bits of dead people and bottles of creatures.”

Not to mention the piece de resistance, a “wooden box with the wax models of the heads of executed murderers. And their hands!” Byatt chuckled at the absurdity. “These murderers are peering over the edge of the box, and their hands are sort of clinging. Four of them, one woman and three men, I think.”

Byatt is not a film buff (though she did like “Mad Max” and “Babe”), but for some reason, while writing the medical short story, she pictured it as a movie, with a cut here, a certain camera angle there. Byatt did not write the screenplay for the film adaptation of “Possession,” which was released last year, starring Gwyneth Paltrow and Aaron Eckhart. In fact, she never has written a screenplay.

But, with the medical story in mind, she bought “a computer program that teaches you how to put out a film script in a painless manner. I’ve invested in it, so....” But she was quick to squelch expectations. “It probably won’t happen,” she said. “You mustn’t make too much of it.”

She also is researching a novel that takes place in the 1880s through the early 1900s, and she is thinking about another novel set in Vienna and New York. “It’s about psychoanalysts, but if I tell it to people, someone might pinch it, so I’m not going to tell you any more,” she said.

Another short story in progress has to do with the bombing blitz of London during World War II.

“That’s the one I’m thinking about as I travel throughout the United States,” Byatt said, “and not Frederica,” the red-haired heroine of her quartet of novels.

A portrait of British sensibilities

Of course, Byatt is pleased when readers at book signings tell her they can’t believe there will be no more stories about the fiery Frederica, a brilliant woman struggling to balance love and work. “They do appear to be upset, which is quite nice,” Byatt said. “They keep saying, ‘Perhaps you’ll do another one.’ And I keep saying, ‘No, I have so many things in my head that aren’t that.’ I tried to make the book have a shape that made it perfectly clear that this was the end.”

The first book in the series, “The Virgin in the Garden,” was published 24 years ago, kicking off what’s known as the “Frederica quartet.” Frederica was introduced as a 17-year-old in 1953, the year of the coronation of Queen Elizabeth II. In “A Whistling Woman,” Frederica is a single mother and host of a TV talk show in the late ‘60s. The book touches on Byatt’s usual litany of eclectic interests, from Tolkien-esque fairy stories to the sexual habits of snails. Critics often describe the four novels in monumental terms, as nothing less than a portrait of British life and sensibilities in the 1950s and ‘60s.

Byatt had dreamed up the quartet as a young mother and wife in the early ‘60s. The books weighed on her for the next four decades, as she married, raised four children (three daughters -- while touring, Byatt managed to visit with one, who lives in San Francisco -- and a son who died in a car accident), divorced, remarried, taught at University College London and completed other writing projects.

“Had I known how much trouble it would be when I thought of them,” she said, “I probably wouldn’t have ever done it because it was stupid to commit so much of your life in advance to one idea.... I had been living with the fear of not finishing it or getting it wrong. I felt quite pleased with the shape of it when I had finished it.”

After an hour of conversation, she warmed up to the topic at hand, how she felt about letting go of Frederica. At the end of “A Whistling Woman,” Frederica is left standing on a moor, in the middle of another life pivot, bare-legged in a cotton Laura Ashley dress.

Byatt has saved all of her notes and manuscripts from the four novels. “Actually, if you want a moment when I felt bad,” she offered, “it was when I put the notebooks for Frederica away in the filing cabinet. And I thought, ‘I shall never put any more in here. I mean, I could, but I won’t.’ And that felt bad.”

*

(BEGIN TEXT OF INFOBOX)

Closure for a quartet

A.S. Byatt’s four-part epic on fiery Frederica Potter and her family, often called the “Frederica quartet,” spans British life and sensibilities through the 1950s and ‘60s:

“The Virgin in the Garden” (Random House, 1979) -- The story revolves around the Potters, a troubled academic English family living in Yorkshire. Daughter Frederica, a bright schoolgirl in 1953, becomes captivated by Queen Elizabeth I and gets involved in a play about her. When the play becomes part of Elizabeth II’s coronation festivities, the small-town pageant gets out of hand. (Synopsis from book distributor Ingram Book Group)

“Still Life” (Chatto & Windus, 1985) -- Frederica Potter plunges into Cambridge University life greedy for knowledge, sex and love. In Yorkshire, her sister Stephanie has abandoned academe for the cozy frustration of the family. Love interest Alexander Wedderburn, now in London, struggles to write a play about Van Gogh. (from Amazon.com)

“Babel Tower” ( Random House, 1996) -- Frederica regrets her marriage to the wealthy Nigel, who becomes so enraged over her Cambridge friends (all men) that he goes after her with an ax. She flees to London with her young son, Leo. Eager to return to the literary life, she teaches part-time at an art school and reads manuscripts for a publisher, including a bizarre, Marquis de Sade-like novel titled “Babbletower,” a work eventually deemed obscene by the courts. Frederica finds herself amid artists fostering dreams of rebellion, which revolve around “Babbletower’s” strange author, the unkempt Jude Mason, a hippie before his time. (Booklist magazine and Random House)

“A Whistling Woman” (Knopf, 2002) -- It is the late 1960s and Frederica, now 33, finds herself host of a very hip BBC talk show. Around her is an array of characters, some rational, others quite mad. There are the unhappy, codependent Ottokar twins, one a mathematician, the other a musician; rock-steady scientist Luk Lysgaard-Peacock; Elvet Gander, a psychiatrist with a taste for lysergic acid; and Joshua Ramsden Lamb, the leader of a Manichean cult. (Booklist magazine)