Undone

Jem's world is shattered. All she has left of her best friend are twelve letters--one for each month of the year--he wrote her before he died. Kai's letters beg her not to investigate what happened, but Jem can't let it go. She needs to know who did this, and she'll stop at nothing to find the person responsible for Kai's death. One way or another, someone is going down. Someone is going to pay...