Spencer, Aria, Emily, Hanna and their best friend Alison were the most popular girls at Rosewood Day School. Alison was the group´s ringleader, the one who knew all their darkest secrets. So when Alison vanished one night, Spencer, Aria, Emily, and Hanna´s grief was tinged with relief.
But when Ali´s body was later discovered in her own backyard, the girls were forced to unearth some ugly memories of their old friend, too. Is there more to Alison´s death than anyone realises? Now someone named A, someone who seems to know everything, is pointing the finger for Ali´s murder at one of them. And A is poised to ruin their perfect little lives . . . for ever.