Kill Chain (Evan Delaney Series #5)

When Evan Delaney finds her father’s car at the bottom of a ravine, the police suspect suicide—but there’s no body. Evan’s suspicions of something sinister are confirmed when she receives a call from her father’s kidnappers. The ransom isn’t money, but more of a puzzle—one that Evan has only 72 hours to piece together, as she follows a madman’s trail into the very heart of darkness.