Medical examiner Maura Isles returns in another thriller that joins past and present. In the present, in the backyard of Julia Hamill's old Boston house, a long-buried body is unearthed. In 1830, long before the invention of the term serial killer, medical student Norris Marshall is accused of being a mass murderer. To dig himself out from under suspicion, Norris seeks help from a fellow student, one Oliver Wendell Holmes. Together they pursue the cold-hearted killer, while, in the present day, Julia Hamill tries to find out the identity of the body buried in her backyard.