Magnus Craig is a human bloodhund.He works in the Special Trackung Unit of the FBI in Washington state. Only his partner knows about his special skill. He refers to it as shine. He sees an aura surrounding crime scenes,victims and the killers.Some people refer to this as signature when the clues are visible. What he sees is invisible to other people.He has put numerous serial killers away over the years. This book reminds me of Criminal Minds---the tv show. This was a solid hit for a start to this series.Characters are introduce with just enough back story to give them a solid foundation without weighing the story down. We are introduce to other cases that show how most FBI units work. Even the ending wraps up a case, shows how violence affects law enforcement and gives a reader a clue for the next case