1992: For nearly a decade, the international assassin known only as "the Wraith" has eluded authorities. Political leaders, powerful heads ofbusiness, terrorists known and suspected have numbered among the many victims until -- without explanation -- the Wraith disappears....

2005: Tom Baldwin and Diana Skouris are investigating Jordan Collier's murder, but they're pulled off the case. Washington believes the Wraith -- a onetime freelance agent for the U.S. government -- is active again. A high-ranking CIA officer, who oversaw the rogue operator's activities, is killed. Evidence at the scene points to the Wraith and that this highly efficient killer is now a 4400. The NTAC agents only have thirteen-year-old leads to follow an assassin who was never caught. Suddenly, the Wraith kills another returnee. Why? What does this mean? Can the mounting fears of the 4400 be right? Or is this just one returnee who has gone off the track. Baldwin and Skouris need to know -- but will they find out before the Wraith completes this deadly covert objective?