Three little girls set off to school one sunny May morning. Within an hour, one of them is dead. Fifteen years later, Kitty lives in an institution. She can't speak, and has no memory of the accident that put her there, or her life before it. Nearby, Alison, a local artisan, struggles to make ends meet and to forget her past. When a job opens up in a prison as an art teacher, she takes it. Soon, though, she starts to receive alarming notes--followed by a frightening prisoner-on-prisoner assault while her back is turned. When an impressive new student arrives in Alison's class, things seem to settle down. But not for long. For someone is watching both Kitty and Alison. Someone who wants revenge for what happened that day. And only another life will do.