Joanna Kavenna's striking debut novel, Inglorious, covers the emotional breakdown of Rosa Lane, a successful journalist in her mid-thirties.

After the death of her mother and acrimonious end to a long relationship, she walks out of her job and her home, going to stay with a friend. As the friend turns increasingly hostile, Rosa spends her days aimlessly, although an increasing overdraft forces her to look for work.

There is just enough plot to move the novel along, including a new younger boyfriend and a visit to married friends in the Lake District. However, the story focuses on what goes on in Rosa's mind as she wrestles with the unanswerable questions of life and death, and compares her own life with that of her parents and grandparents.

Joanna, 34, writes with dark wit and fluid elegance about an ordinary woman's dark night of the soul.

Why did she want to write about Rosa and her travails?

It is partly because of books by Camus, Kafka and D.H. Lawrence. "I grew up reading these books by male writers about male protagonists having these existential dilemmas," she said. "I never found any books by women, so I thought it would be interesting to try to write a book using a female protagonist, but to try to ask these questions that are regarded as the human condition questions."

It is also because of Joanna's own life experience. "The facts of Rosa's life were not mine, but her philosophical bent - that slightly melancholy, dark humour-kind of questioning - I understand," she said. She has seen people living outwardly successful lives who question their life after a major upheaval such as those experienced by Rosa. "There's a moment when you think: What would make me happy? What would be a good way to spend my span of years?" Such questions work their way into the book.

Was Rosa experiencing anomie - alienation and a purposelessness that afflicts many in society?

"Yes, it's exactly like anomie. There's this kind of curtain between you and normal life and you can't quite open it and get back in."

She sees Rosa's journey as a heroic epic, where the hero leaves the confines of their safe life and goes out into the wilderness. "A very ordinary person can have their own epic trials. It's not just kings and princes and heroes," she said. With that in mind, she manages to maintain one's sympathy and interest for Rosa - no small feat when the character is so inward-looking - and it is easy to see why Inglorious was shortlisted for the John Llewellyn Rhys prize for Commonwealth writers under 35. The winner will be announced in London on November 29.

Joanna came to Oxford ten years ago to do a doctorate at Linacre College and has been here on and off ever since; at one time she spent a fabulous year on a writing fellowship at St Antony's College set up by the historian Alistair Horne. However, much of the time has been spent travelling, working as a freelance journalist and writing unpublishable novels. "I wrote a novel about the Osiris legend that was in an imagined place," she said. "I made up the language, so all the characters spoke to each other. It was completely mad; you could only understand the novel if you understood this mad language I'd created."

She found it rather a shock, therefore, when she managed to sell an idea for a non-fiction book, without having written a word. "That seemed very strange after years of writing novels and not being able to get them published, to suddenly be given an advance on the basis of a proposal. It was almost as if my bluff had been called." The Ice Museum, published in 2005, is a travelogue set in northern Europe, about the search for the mythical land of Thule, inspired by an ancient Greek traveller.

She is currently working on another piece of fiction. "I keep returning to this idea of when you throw your life in the air and go off. You can really only have one life, but you always have in the back of your mind, what would it be like if I was having this other kind of life?

"I've always moved around a lot, perhaps in search of the perfect place." When I asked if she has found it, she replied: "Well no, because you're always yourself and take yourself from place to place, so you're never a perfect person, but I suppose you have a different range of experiences and you realise that it's possible to be quite happy in a lot of different places if the conditions are right."