The Vesper and Cahill families are at it again. With Baldacci at the helm of the last volume, the pulse-pounding pressure may be too much for Dan and Amy Cahill to overcome. Seven Cahill hostages have been taken by Vesper One, their release is promised in return for a series of bizarre ransoms. Once the Cahills find the last clue, they realize that the Vesper's plan is more diabolical and heinous than they had originally thought and that it could destroy millions of people. The race against time splits the group in two directions: one group off to find the hostages in the Cascade Mountains while Dan and Amy travel to D.C. to head off Isabella, who they suspect to be Vesper Two. Finally, they meet up under the Rocky Mountains for the hair-raising standoff between good and evil. The squabbling for control within the Vesper camp and the strained loyalties among the Cahills creates an emotional frenzy that makes the book hard to put down. It is up to the few remaining Cahills to decipher the clues, solve the puzzle, find their missing friends, and save the world. The author injects a healthy dose of history, geography, and geology into the storyline.