The Stepdaughter by Caroline Blackwood

A lavish Upper West Side apartment is the site of a familial cold war about to enter a phase of dangerous escalation.

J is a lonely woman without the luxury of being alone. Her husband has fled to Paris with his latest flame, leaving J with not only their own four-year-old daughter, Sally Ann, but the sulky, cake-mix addicted, thirteen-year-old Renata, a leftover from his previous marriage.

Writing letters in her head to imaginary friends, J delights in dwelling on the hapless Renata, who 'invites a kind of cruelty'. This is an invitation J fully intends to take up - and like so many stepmothers before her, she will find that wickedness, once indulged, is a difficult habit to kick. A mordant black splinter of a book, Caroline Blackwood's first novel is a testament to her razor-sharp mastery - and mockery - of the darkest depths of human feeling.