Carlton Book is an accountant. He conducts his life as he does the spreadsheets he works on, with careful review of all the variables. His philosophy serves him well in his other profession: an assassin. When he goes to his next 'assignment' he finds his target has already been murdered by a serial killer known as 'The 3-Monkey Killer'. Book must now find the killer before the killer finds him, and before he is arrested for the psychopath's crimes. And before his own crimes are revealed.