A Box of Letters by Andrea Anderson

From the time she understood what the word "adopted" meant, Rayna has wanted to find out who her birth parents were. The only information she has are a box of letters written in a foreign language, given to her by her adoptive mother. After finding a translator, Rayna finally learns the truth of what information is in the letters. As the letters are translated by Stanley she becomes attached to the letter write although it appears she is not her birth mother, As the letters are read they reveal more questions than answers, and dark secrets begin coming to the surface about the person who has written the letters. Soon after reading the letters, a series of murders happens around Rayna. Not knowing if the two events are connected, Rayna will become fearful for her own life when a third victim shows up dead—with seemingly no answers to speak of.