On her twenty-third birthday, Ariana receives a letter from her dead father. “If you are reading this, I am already dead. Do not trust anyone in our family. Tomorrow, you will receive another letter.” The next day, another letter arrives. Then another. Her father left behind 365 letters—one for every day of the year. Each letter reveals a piece of a secret he took to his grave. Some contain warnings. Some contain instructions. And some reveal truths Ariana wishes she had never known. When she meets Leon, a mysterious stranger who seems to know far too much about her father's death, Ariana doesn't know whether to trust him or fear him. But then she discovers something impossible. Her father wrote only the first 200 letters. Someone else is writing the rest. And whoever it is... knows everything about her.