The Dead Letters, Book 1

In the Atlanta dead-letter office, a series of odd letters began to arrive from Seattle. The envelopes were addressed simply to "sister" with no address or return address and inside, the letters were signed by someone who called herself, Princess. Yet, the contents of the letters seemed to be a cry for help, and soon it became Natalie's obsession to find her. For that she needed the help of a detective - a very handsome detective named Daniel.