The Moth Diaries By Rachel Klein Faber and Faber, $120 School-based coming-of-age-stories are much of a muchness: whatever the plot, the atmosphere is often hormonally charged, with homosexual crushes a given. Then there's the language. For authenticity, the author must capture the naivety of youth. The Moth Diaries is all of the above with a twist of madness. Set in a private US girls' school during the 1960s and written in diary format, it tells of a boarder who has recently lost her father to suicide. Before the diary begins, she informs us that her psychiatrist has suggested she publish her journals, which is why she's returned to them 30 years later. Mental illness is, therefore, always on the cards. Insanity takes the form of hallucinations about a new girl, Ernessa, who fastens on to the narrator's best friend. Ernessa's strange hold prompts the narrator to believe the girl is a vampire and that she should 'thrust something into her heart'. A dark and disturbing novel that probes reality, and the lunacy that skirts it, The Moth Diaries provides an insight into the minds of teenage girls. But it might leave older readers searching for relevance.