"This story came to me years ago. It's based on a book I wrote in Welsh and it depicts life during World War II in north west Wales.

I've always had an interest in art and, living in Bangor, I knew that the paintings of the National Art Gallery in Trafalgar Square had been moved to north Wales. They were taken to Pritchard Jones Hall and Penrhyn Castle in Bangor, but when the Germans started the bombing they were moved on to caves in the mountains of Manod, near Blaenau Ffestiniog.

I did do some research into the storing of the National Art Gallery's paintings during the war. I read the autobiography of Sir Kenneth Clark, the director of the National Art Gallery who was in charge of ensuring the pictures were safely moved from London to Wales.

In 1942 when the bombing ended in London (except for the doodlebugs which came later on), they decided to bring one painting each month down from Manod to exhibit in the gallery. They wanted to brighten the lives of the pople who had suffered so much.

Even though the gallery had been damaged, they still held daily lunchtime concerts there as a chance for the people to escape everyday wartime life and enjoy music and art.

So I got the idea of someone stealing one of these paintings as they were transported from Manod to London.

There were a lot of secrets during the war due to necessity. There were posters saying 'Careless talk costs lives' and 'Be like dad - keep mum'.

But Sabel, the main character of In the Dark does ask questions. She's a 13-year-old girl who's determined to solve the mystery of the missing painting. But she doesn't know if the people who are involved in transporting the picture are spies or Germans who had escaped their country before the war.

The mystery is intensified because the pictures were always carried in falsely marked lorries to hide their real cargo - they had slogans like 'Knights Castille for face appeal', a famous soap, on them.

Of course, I didn't know about this at the time - I was a schoolgirl in Penmaenmawr during the war. I was aware of the evacuees who came in 1939, though lots returned to Liverpool after a few weeks because the bombing didn't begin straight away.

But lots of other people stayed, especially civil servants and their families from London. They took over the large hotels of the coastal towns, like the Grand Hotel in Penmaenmawr. It was a beautiful building, based on a French chateau. It's a real shame that it's gone now.

The BBC's light entertainment section also got moved to Bangor, so there were lots of bohemian, artistic-type people wandering around, the likes of which I'd never seen before.

So the war was quite an exciting time for a young girl like me. I didn't have an older brother to worry about and the war was very distant, something that was happening far away from home."