A year ago Sophie Malone was left for dead in a blood–soaked Irish cave. Haunted by her experience, she immerses herself in her archaeology research. But now the fabled Celtic treasure she believes disappeared from that cave has resurfaced in Boston, in the hands of a serial killer. Was he responsible for that night of terror...for the whispers she heard in the dark?

Boston detective Cyrus “Scoop” Wisdom has recovered from an explosion that nearly took his life. Now he's after the person who planted the bomb– and he thinks it's another cop. When Sophie finds his chief suspect hanged in a vicious ritualistic manner, Scoop's suspicions turn toward her.

Sophie and Scoop must push aside their differences and make the connections between missing ancient artifacts and modern–day forensic evidence left at each scene...before the killing starts again.