Copycat murders. Wren Delacroix doesn't like them. They aren't easy to profile, and this one is no exception. Whoever killed Oliver Campbell had intimate knowledge of Major Hill's murders, and Wren can't be sure who that could be. To make matters worse, Wren isn't experiencing her typical eagerness to solve this case. Instead, thinking about it fills her with a crushing dread that seems to consume her. It's as if she knows that once she solves it, things will never be the same. The trail of this killer sends Wren and Reilly tunneling into the past, to speak with Vivian Delacroix in prison, and eventually deep into the woods outside the compound, where they find a threat of blood and bone that spirals into chaos and violence. Soon, they are fighting for their very lives.