Anna Maria Dane is a woman who is struggling with despair after losing her father and fiancé in the attacks of September 11, 2001. Her pain turns into anger, which gives birth to a desire for revenge, and she obtains it in the only way she can, by going after individuals still alive who helped bring that day about. She gets amazing and unusual assistance from Braeden Maguire, a guilt-ridden CIA operative, whose reasons for helping her are not what they seem. Anna Maria's killing spree takes her to some of the most beautiful and dangerous places in the world, and the things she discovers people did to help the hijackers carry out their mission astonishes her. But killing these people does not bring her peace, so she sets out to confront the terrorist leader who masterminded the September 11th plot. Killing this individual, a man whom the CIA has dubbed "The Most Dangerous Man Alive", is not easy and she herself is almost killed. So close to death's door and willing to stay there, the people around her refusing to give up on her, Anna Maria soon comes to realize that living is the best revenge of all.