Book excerpt: Now, available for the first time together in a single volume: a digital-only, value-priced omnibus edition of the Helen Trilogy: Fever Dream, Cold Vengeance, and Two Graves-featuring Special Agent Pendergast--by #1 New York Times bestselling authors Preston & Child. FEVER DREAM:Yesterday, Special Agent Pendergast still mourned the loss of his beloved wife, Helen, who died in a tragic accident in Africa twelve years ago. Today, he discovers she was murdered. Tomorrow, he will learn her most guarded secrets, leaving him to wonder: Who was the woman I married? Why was she murdered? And, above all . . . Who murdered her?Revenge is not sweet: It is essential. COLD VENGEANCE:Devastated by the discovery that his wife, Helen, was murdered, Special Agent Pendergast must have retribution. But revenge is not simple. As he stalks his wife's betrayers--a chase that takes him from the wild moors of Scotland to the bustling streets of New York City and the darkest bayous of Louisiana--he is also forced to dig further into Helen's past. And he is stunned to learn that Helen may have been a collaborator in her own murder. Peeling back the layers of deception, Pendergast realizes that the conspiracy is deeper, goes back generations, and is more monstrous than he could have ever imagined--and everything he's believed, everything he's trusted, everything he's understood . . . may be a horrific lie.Nothing is what it seems. TWO GRAVES:For twelve years, he believed she'd died in an accident. Then, he was told she'd been murdered. Now, FBI Special Agent Aloysius Pendergast discovers that his beloved wife, Helen, is alive. And Pendergast must embark on a furious cross-country chase to rescue her. But all this turns out to be mere prologue to a far larger plot: one that unleashes a chillingly--almost supernaturally--adept serial killer on New York City. His pursuit of the murderer will take Pendergast deep into the trackless forests of South America, to a hidden place where the evil that has blighted both his and Helen's lives lies in wait . . . a place where he will learn all too well the truth of the ancient proverb:Before you embark on a journey of revenge, dig two graves.