The Machiavelli Covenant — Allan Folsom

Nicholas Marten's former girlfriend is mysteriously killed--along with her child and congressman-husband. A former LA cop, Marten learns her husband had just discovered a secret and illegal bioweapons program. When the feds fail to investigate, Marten pursues the killers himself.
At a NATO summit in Warsaw, President John Henry Harris meets with Europe's heads of state. When Harris learns secret a White House cabal has ordered the German chancellor's assassination, he angrily objects. The cabal not only threatens to kill Harris, they pull the secret service off his detail.
Escaping incognito, he joins two strangers--Nicholas Marten and the beautiful but enigmatic French photo-journalist, Demi Picard. Swept from Warsaw to Washington, D.C. to Malta to Barcelona, the three of them flee a ruthless clique of military leaders and transnational corporate chieftains--as well as top Washington officials--all of whom want them dead. . . The assassination of world leaders, the massacre of millions, assaults on the US with weapons of mass destruction--nothing is beyond the coterie's cunning.
The group's origins go back 500 years. In the 16th century, the dying Machiavelli fashioned a sinister work entitled, The Covenant--an ominous plan for gaining true power and keeping it. For centuries this wealthy, despotic order has hidden the plan away, inspired and emboldened by its bloody insights and near-preternatural power. Bonded by vicious rites and ritual slaughter, dedicated to their vision of global rule, they have over the centuries prospered beyond dreams of greed and domination. Three people now stand between the Brotherhood and its final apocalyptic conquest.