Three casinos. Three bodies. Three days.
After a string of brutal murders in Las Vegas, Cassie Hobbes and the Naturals are called in to investigate. But even with the team's unique profiling talents, these murders seem baffling: unlike many serial killers, this one uses different methods every time. All of the victims were killed in public, yet the killer does not show up on any security feed. And each victim has a string of numbers tattooed on their wrist. Hidden in the numbers is a code-and the closer the Naturals come to unraveling the mystery, the more perilous the case becomes....

When Cassie Hobbes joined the FBI's Naturals program, she had one goal: uncover the truth about her mother's murder. But now, everything Cassie thought she knew about what happened that night has been called into question. Her mother is alive, and the people holding her captive are more powerful-and dangerous-than anything the Naturals have faced so far. As Cassie and the team work to uncover the secrets of a group that has been killing in secret for generations, they find themselves racing a ticking clock. New victims. New betrayals. New secrets.
When the bodies begin piling up,...