Escalating events begin when U.N. interpreter Silvia Broome alleges that she has overheard a death threat against an African head of state, spoken in a rare dialect few people other than Silvia can understand. With the words "The Teacher will never leave this room alive," in an instant, Silvia's life is turned upside down as she becomes a hunted target of the killers. Placed under the protection of federal agent Tobin Keller, Silvia's world only grows more nightmarish. As Keller digs deeper into his eyewitnesses' past and her secretive world of global connections, the more suspicious he becomes that she herself might be involved in the conspiracy. With every step of the way, he finds more reasons to mistrust her. Is Sylvia a victim? A suspect? Or something else entirely? And can Tobin, coping with his own personal heartache, keep her safe? Though they must depend on one another...

Their vengeance is relentless, their method is ritual, their weapon is secret, and the motive is in their blood. In a heavily wooded private estate in the Malibu Hills, towering above the tumbling Pacific, millionaire CEO Kenji Takeo and his daughter, Miko, prepare for the arrival from Japan of Takeo's wife, Kumiko. But the calm of Solstice Canyon is shattered by a meticulously planned stealth attack on the Takeo home by a masked band of ninja assassins. In a flash, Takeo's guards are killed. The mansion is overtaken, Takeo is killed, and Miko is left for dead. Arriving at the bloody scene is Detective Jack Barrett who encounters Miko-the only living witness. In a state of shock, she repeats only one word like an eerie mantra: kokushibyu. In her native language, it means Black Death.