When seventeen-year-old Katherine McCall awakened one morning to find her beloved sister, Sara, brutally murdered, her whole life changed in the blink of an eye. Kat was named the prime suspect and, on a string of circumstantial evidence, charged and tried. While the jury found her innocent, not everyone else agreed, and her only choice was to go into hiding. But she carried a dark secret with her, one that made her worry she might actually have had something to do with Sara's death. Now, years later, Kat is still haunted by her sister's unsolved murder and continues to receive chilling anonymous letters, but she has tried to move on with her life. Until, on the tenth anniversary of Sara's death, she receives a letter that makes the past impossible to ignore: "What about justice for Sara?"