'Good Me Bad Me': keen psychological thriller about damaged children & what made them so

When Ali Land sent off her rather scant psychological thriller to an agent she expected it to be rejected but was hoping for some useful feedback. She'd written it over months in the small hours of the morning after coming home from her work as a children's mental health nurse.

It was a Sunday afternoon. The agent responded that day. By the end of the week it had been sold to nine countries.

But that was just the beginning as the publishers asked her to double the length of the novel - it would be a further eight months of intense writing and editing to get it into shape.

"I had to give up nursing for a few months to have the psychological strength to do it," she says in a call from London. "I couldn't keep working with damaged children all day and write too."

Good Me Bad Me hooks the reader from the first page.

Annie's mother is a serial killer of children and in the opening scenes Annie turns her in to the police.

With her name changed to Milly, she is placed with a foster family until her mother's trial some months on.

Told in the first person, we live in Milly's mind as she tries to make a fresh start.

"I based Milly on a girl I treated years ago," says Land. "Her mother was involved in serious harm to children, and this girl - she was 15 - eventually confessed that inside she felt she was a different colour from other people; that no matter what, she would be just like her mother. So the character of Milly marinated for years in my head."

It's no shiny, happy family that she is placed with. The father Mike is Milly's psychologist, a good, well-intentioned man who is in denial about his own family. His wife is depressed and drugged and his daughter Phoebe is a sly bully. She makes Milly's life hell at school.

"I want people to ask why," Land explains. "Why is Phoebe like she is? She's at the top of the ladder but that brings its own pressures. Milly is at the bottom. Both of them are the products of their mothers."

Struggling to survive at school and determined to be "good", Milly dreads the trial not only because she will encounter her mother again, but will be sent to another family. As toxic as this one is, she cannot face any more change or rejection. And because we are living in Milly's head, we know she's not as good as she seems to be.

This is where Land is particularly brilliant, sowing doubt in the reader's mind about her character. Can she be redeemed? After all, she had the courage and morality to shop her mother to the police.

"The desire to be good is not enough when the mind is so warped. Is she handling the hurt, or will she hurt someone?"

Land was determined that the book should raise questions about these vulnerable children, of whom she has known many over the years.

"In real life Milly would not be placed with a foster family. She'd be locked up in a secure unit until she was 18. I want people to think about what should be done with these children? They're the product of the adults that raised them. We should punish the adults too. In Scandinavia such children are absorbed back into the family and are visited by therapists and given the chance at a normal life."

The novel builds to the trial and a crashing conclusion that does, indeed, raise questions about the nature of good and bad, of redemption and survival in a harsh world.

"I've seen some kids do well," she says, "but for others it's too late. You never really know what's going on inside them."

• Ali Land will be appearing at the Open Book Festival in Cape Town from September 6-10.

 • This article was originally published in The Times.