In Cambridge, at the edge of the Fens, the Cam has not burst its banks, despite three solid days of rain. Murky green, it brims but keeps its course, flowing sluggishly beneath the willow behind Jill Paton Walsh's deceptively plain townhouse. Approached from the street side, the house is one in a tight row of modest brownstones, but inside, the kitchen and the sitting room give directly onto the river and Midsummer Common beyond. Through the large windows, the life of Cambridge--its river, its townsfolk, its students--plays out in a view that might inspire a writer stuck between chapters.

And we find ourselves drawn to the window straight away, as Jill Paton Walsh, a brisk, warm, lively 63-year-old, explains some of the lesser-known aspects of punting on the Cam. She's erudite in the effortless way that comes from a lifetime of reading combined with natural curiosity and a zest for knowledge. Within minutes we've jumped from punting, to the drainage of the Fens, and on to the great engineer Isambard Kingdom Brunel and the prefabricated hospital he designed for the British forces in the Crimea. Her passion for knowledge is neither showy nor tedious, and it informs all of her meticulously researched and imagined fiction.

Her new novel, A Desert in Bohemia (St. Martin's), took almost 10 years to write from initial spark to final draft, requiring extensive research and three visits to the Czech Republic. Although the novel is set in a fictional Czech region called Comenia, it was at a Prague cocktail party that Paton Walsh first heard the anecdote that inspired the novel. It was 1990 and the week of the first post-Communist elections in Czechoslovakia; the country was like "Sleeping Beauty's castle in the second before they wake up," as Paton Walsh says. In the course of that evening, someone told her the story of an elderly aristocrat, banned from crossing the frontier under Communism, who returns to his ancestral home and asks the authorities if he may have a laundry basket containing some papers belonging to his father. He is told that he may have the laundry basket only if he reclaims the whole vast house. "It struck me," Paton Walsh says, "that the process of returning property to the dispossessed was an attempt to pretend that the last 44 years hadn't happened." The question of turning the clock back nagged at her like "a wasp in a jam jar." The idea went into "cellarage," and then three years ago she began to commit it to paper.

The result is an ambitious novel following the fates of characters who come from the Comenian upper, middle and working classes. It begins in 1945 with the startling, filmic image of a blood-drenched girl emerging from the woods on a misty morning and running for refuge toward a white castle. The castle and the girl do not belong together, yet the castle offers her shelter, and she in turn saves the only thing of real value amongst its deserted treasures: a baby girl, just weeks old, hidden beneath the kitchen table. After this opening, a satisfying saga is assured. Where's the baby's mother, who's the girl, why is the girl covered in blood and why can't she remember who she is? But this is not a novel, in blurb-speak, set against a backdrop of wartime hardship in Czechoslovakia. It is, rather, a novel about the choices people are forced to make when authoritarian ideologies take away their free will. That a novel should be about ideas as much as is it about characters and plot is important to Paton Walsh. "What gets me is a story or an anecdote that has a moral shape," she says. "I think that novels are tools of thought. They are moral philosophy with the theory left out, with just the examples of the moral situations left standing." Referring to a recent case before the British courts regarding the fate of conjoined twins who needed separation surgery to save one of them, otherwise both would perish, she adds, "It's easy to say 'Thou shalt not kill,' but it's very difficult to decide what to do about a pair of Siamese twins. The exact circumstances of the twins is what makes moral thinking difficult. I'm trying to think about the human situation and am inviting readers to think and feel with me."

The enigma of Paton Walsh is that this most writerly of writers did not set out to be one at all. Born Gillian Bliss in London's North Finchley in 1937, she grew up to be quite definitely her father's daughter. John Bliss was a brilliant self-made man who came from working-class stock, fought for an education and went on to become something of an engineering genius. He played an important role in British radar defenses during WWII and later became a pioneering designer with BBC television. "He had one superlative advantage from the point of view of a daughter, which was that he wouldn't let you off easy on anything on the grounds that you were a daughter and not a son," she says. "He expected great things of me, which was very unusual in his generation, and it was a great empowerment."

Young Gillian could read by the age of four, and by 11 she was reading Aeschylus behind the sofa. "My grandfather had a proper bookcase of egghead books, and he gave them to me in alphabetical order. So we moved from Aeschylus to the Brontës, and I can still remember the great relief of going from the dipus cycle to Jane Eyre."

But trouble was lurking around the corner: enter a troupe of ex-pat relatives thrown out of Burma by the Japanese. They had nowhere to go, so Jill's mother took them in. Three families, one house. The Burmese relatives had very different ideas of how little girls should be. "They plainly detested me," she says. "They did not think it right for a little girl my age to be reading Greek drama. Because of them, she "came to completely despise nonintellectual views of the world for a long time. I thought, why should I defer to them?... They're pig-ignorant philistines." She believes now that these were very unattractive thoughts in a small girl but admits, too, that it was this rage for intellectualism that saw her compete successfully against 500 others to win one of 12 places at St. Anne's College, Oxford. Like her father, Paton Walsh won her education against the odds of her "crummy" convent education where no other girl had gone up to university before. "Remember, Gillian," one despised nun would say, "there is no beatitude 'Blessed are the clever.'"

For a very long time, Catholicism was important to Paton Walsh, right through Oxford, where the nuns expected she would lose her faith. But daily mass didn't stop her from devouring the intellectual delights of Oxford. Thinking a degree in Modern English Literature would not tax her sufficiently, she opted instead for the masochistic pleasures of Medieval English and Linguistics. Amongst her contemporaries were Alan Bennett, Penelope Lively and Nina Bawden; amongst her teachers, J.R.R. Tolkien and C.S. Lewis. But towering above them all was Iris Murdoch, who was a fellow of St. Anne's, and possibly the writer Paton Walsh regards most highly. Murdoch's Sovereignty of Good (1970), in particular, has obvious resonances for Paton Walsh.

After Oxford, Paton Walsh took a job as a teacher in a girls' grammar school but soon married the man who made her Paton Walsh instead of Bliss. By 1962, she had a baby and was at home all day feeling "driven to distraction by a slack intellect. I thought I was going to rot between the ears and have the sides of my head fall in." There was nothing for it but to write. Innocently, she is asked if this was the first time she had a desire to express herself creatively, and it's obvious within seconds that the question raises her hackles. "I have never had such a desire," she replies archly, "and I still don't have such a desire. If you want to express yourself, you need the services of a lover or a psychiatrist; if you want to express a book, you might conceivably manage it." At last she smiles, relief all round. Warming to her subject, she adds, "You can't deduce the personality of the potter from the pots. It's a thingy you've made and offered to somebody else for their use, and, believe me, a novel is like that. It's a made thing and ought not to contain a direct self-expression of the writer. It ought to be an object crafted out of a passion for the subject and a knowledge of the audience. If you put self-expression into it, you're writing a certain kind of thing, which is current but extraordinarily self-indulgent. It's too personal; it won't do as a model of art."
In any case, she did write during those years. In the beginning, it was children's fiction inspired by the Anglo-Saxon heroic cycle (Hengest's Tale, St. Martin's, 1966), but as she developed so did her themes and settings. The Emperor's Winding Sheet (FSG, 1974) shared the Whitbread Prize in 1974, and Unleaving (FSG, 1976) won the Boston Globe-Horn Book Award.

Fifteen years ago, her marriage ended and her career in adult fiction began with the publication of Lapsing (St Martin's, 1987), a painfully autobiographical novel that demanded to be written. It was around this time, too, that she had a first meeting with a Books Page editor at the (then) Manchester Guardian. He was the writer John Rowe Townsend, and he has been her partner and sine qua non ever since.

Having served a long apprenticeship as a scribe, Paton Walsh had by now a reasonable income from her work, a wonderful agent and surrogate brother in Bruce Hunter of David Higham Associates and a feeling of security with her publisher. Informed by 26 years of convinced Catholicism, Paton Walsh began work on Knowledge of Angels (Houghton Mifflin, 1994), the book she "was born to write." Religious faith and belief systems inform this novel about a wolf girl, an atheist and a devout theologian. The theologian hopes to use the former to persuade the latter that innate knowledge of God is found even in the heart of the most degraded human. The novel came in a torrent, spending no time in the mental cellars, and was written in four months. It was a flawless gem.

But therein lies a tale, because when Paton Walsh presented it to her British publishers, Weidenfeld & Nicolson, they turned it down with the flimsiest of reasons. Soon a friend put it under the nose of an editor at Houghton Mifflin, and it was snapped up for the U.S. market. Armed with this encouraging news, Hunter sent the manuscript on a tour of other London publishers. Somehow, though, word was out, and it kept coming back with "silly rejection slips like 'This book will still be read in 20 years' time but I can't publish it' or 'We have already published our Booker submissions for this year and do not otherwise publish literary fiction.'" "Fuck this," said John Townsend, "we'll publish it ourselves." They already had their own imprint, Green Bay Publications, which they used to publish noncommercial critical work relating to children's literature, and with the help of some friends, 1,000 copies of Knowledge of Angels hit the bookstores. A brilliant publicist worked for reduced fees, copies went off to the Booker Committee, and the novel was shortlisted. Blessed are the clever. Knowledge of Angels didn't win the Booker, but Jill Paton Walsh was a made writer.

In the midst of all this, with A Desert in Bohemia rattling in the cellar, Paton Walsh was still producing regular books like the good craftsman she is. In the 1990s, she also dipped her t in the sleuthing pond with The Wyndham Case and A Piece of Justice (St. Martin's, 1993 and 1995), and her quaintly old-fashioned, quintessentially English creation, nurse and amateur sleuth Imogen Quy, was welcomed to bookshelves by the crime cognoscenti. The new arrival was not lost on the guardians of the estate of the late Dorothy Sayers, who were on the lookout for someone to complete a 170-page manuscript Sayers left unfinished. It was a poisoned chalice--P.D. James had already turned it down--but gamely, Paton Walsh took up the challenge and turned out a clever and plausibly Sayers-like novel in Thrones, Dominations (St. Martin's, 1998). The book was a bestseller in the U.K. and U.S. Sayers fans had waited a long time for this, and again Paton Walsh had turned daunting odds in her favor.

These days, in rainy Cambridge, Jill Paton Walsh sits companionably in the study she shares with John, working on another Lord Peter Wimsey whodunit. The working day g s from 8:30 to 1, then it's time for lunch; chores in the afternoon, reading from 5 to 7, followed by Scrabble, music, cinema or the kind of disputatious dinner parties favored by this amiably argumentative household. Finally, the rain over, the house quiet, silent work starts up in the cellar again.

Nolan is an Ireland-based freelance journalist with a background in public broadcasting.