The Jefferson Prophecy — Tom Lowe

When an encrypted letter written by Thomas Jefferson is found hidden in the attic of an old farmhouse in Virginia, the information could offer a clue as to who killed a U.S. Special Forces soldier 220 years after the letter was written. Paul Marcus, who five years earlier, broke an coded paper written by Isaac Newton, is asked to see of he can unlock the secret Jefferson had originally meant for one person in 1804. More the two centuries later, the great, great grandson of the first man to declare war on America, vows to fill a family vendetta and again declare a holy war on the United States. The encrypted letter Jefferson wrote, hidden for two centuries, could offer a key to a new murder that threatens to tip the dominos and start a war. All Paul Marcus has to do is find a way to decode the letter, and he has very little time to do it.