Around the world, twenty-two people have been murdered. The victims fit no profile, the circumstances vary wildly, but one thing links them all: in every case the victim is branded with a number. With police around the globe floundering and unable to identify any pattern, let alone find a killer, CIA Analyst Quinn Mitchell is called in to investigate. Before long, Quinn is on the trail of an ice-hearted assassin with seemingly limitless resources - but she's prepared for that. What she isn't prepared for is the person pulling the strings.