Thousands of miles from home, Isa sees a man who looks intensely familiar. After she thwarts an attempt on her life, she escapes down the mountain with the familiar man, Xander, and he explains about four ancient bloodlines, each with its own unique set of skills: Cicero, Solomon, Sun Tzu, and Lilith. He belongs to a secret society devoted to observing and recording, but never interfering. Until now.

As Isa fights to survive, she grows close to Xander. She learns of her abilities passed down through blood and struggles to uncover the truths of her past. She decides she has to put a stop to the killing of the bloodlines and protect Xander from any further harm...even if it kills her. But will the truth of the killer's motivations and identity be too much to handle?