When the sister of the judge presiding over a sensational murder case is found dead, chief medical examiner Kay Scarpetta, the reluctant star witness in the trial, investigates and recognizes telltale signs of the unthinkable, pitting her against a powerful force that returns her to the past.

In Alberta, Canada, an eminent paleontologist disappears from a dinosaur dig site, and at the Cambridge Forensic Center, Kay Scarpetta receives a grisly communication that gives her a dreadful reason to suspect this may become her next case. Then, with shocking speed, events begin to unfold. A body recovered from Boston Harbor reveals bizarre trace evidence hinting of a link to other unsolved cases that seem to have nothing in common. Who is behind...