Kate Long, author of The Bad Mother's Handbook, has a fourth book due out in March 2008.
Titled The Daughter Game, it features Anna, a woman in crisis. Her marriage is struggling, and the affair she began as consolation has now become a burden. She is happiest while teaching.
Then a beautiful fifteen-year-old named Kali arrives in her English group. Kali is bright, intense, and vulnerable. Anna takes Kali under her wing, but soon the friendship turns into something more unsettling...
It sounds a little like Notes on a Scandal. I'll be interested to see what Kate does with the subject.
Related post: The Bad Mother's Handbook on TV
