The gruesome murder of a history professor at Cambridge University reveals a sinister secret that has been kept hidden from the world for almost six centuries - a secret so powerful and valuable, that people are willing to kill for it, even today.
One day after the gruesome murder of a history professor at Cambridge University, his protégée Dr. Andrea Hendrickson, receives an anonymous parcel containing century-old letters, penned centuries ago by the most powerful men of their time: Kings, emperors and popes. The consignment is accompanied only by a note: "Be careful."
Convinced that the letters and the cryptic note are in some way connected to her mentor's death, Dr. Hendrickson embarks on a quest to uncover the truth. Stunned she finds that her mentor, an inconspicuous historian, had been hunting for a secret so dangerous, that centuries ago, the Roman Catholic Church, together with the kings and emperors that ruled over the Christian lands, decided that it had to be hidden from the world forever.
The moment Dr. Hendrickson starts to delve in the murky depths of history, she finds that she herself has become a target. As the obscure treasure hunt suddenly turns into deadly reality, the historian is unwittingly plunged into a world she never believed existed: A world in which in which history has the power to kill and in which the legend of Vlad the Impaler, the 14th-century Wallachian prince who inspired the tale of Dracula, is still very much alive.
Her desperate search for the truth, leads her from the ancient university archives of Cambridge, to Rome and Florence, and from there to Vienna, Istanbul, Budapest and finally to a remote monastery in the Fagaras Mountains, at the heart of what was once the principality of Wallachia.