SECOND THOUGHTS / Walking the mean streets: Gillian Slovo reflects on how the feisty heroine of her detective fiction has changed over the years

IT STARTED as a whim. With Facade, my psychological thriller, on the copy editor's desk, I needed another project. Why not, I thought, go back to my detective? After all it had been seven years since I had last worked with her.

She was my first creation. Kate Baeier: a modern, feisty, fearless woman who walked the mean streets. She was a match for Chandler's Marlow but not his equal in macho. While Marlow was a loner, Kate had a supportive partner, stepson, good friends. Although she went out there alone there was always someone waiting when she returned.

It was a bold attempt to modernise the myth, but not without its problems. At the same time as her social life made her, it also restricted her: if you're a mythical character, you need to deal with murder and mayhem without casual breaks for tea and gossip. Her friends were, plotwise, too demanding: they would have to go. And go they did - packed off to America, leaving Kate to deal with the after-effects of loss. Not too much loss though. Her partner, Sam, lived on.

After the third in the series, I left Kate. I had other, different kinds of stories to tell. And I was straining against the constraints of the genre and of the woman I'd invented. I had no other choice: I hung up her walking shoes.

And then it came again: that whim to make her live. I had to change her though, to bring her up to date. I wanted to give her more edge, more bite, more to lose. I reflected on my original ambition - to create her in her social world - and I thought about the way that, although the friends had gone, Kate was still secure with Sam. Too secure perhaps? What would happen, I wondered, if Sam was no more? What would happen if Sam was dead?

As soon as it occurred, I knew the idea was right. Kate without Sam would have the edge that I'd been searching for. Kate on her own would drag her past with her - and that past would be a jagged one. So Sam died and that made Catnap (Michael Joseph, pounds 9.99) possib1e.

I'd come full circle, back to my first love, to Hammet and Chandler, and to the realisation that detective fiction is a mythic form created for a loner. With one annihilation, she had become meaner, the streets had become more dangerous, and I had rediscovered why I loved the genre.