The World Demographic Institute, or WDI, based in Washington, DC, is devoted to global conservationist issues, ranging from the balanced preservation of natural resources to population control. In opposition are many religious and conservative individuals and organizations, at least one of which is prepared to resort to violence and chicanery to press its issues and aims. As a result, the WDI has its open, or public, side as well as a clandestine force staffed by professional undercover agents from around the world.
The secret side of the WDI swings into action when first one, then a second of its agents is detected and eliminated. Since the Institute does not know who or what they are fighting, they turn to an unlikely candidate to identify and track down their adversary. He is ex-Army Ranger Francis Xavier McNulty, who has become an activist priest.
McNulty ferrets out a mole in the WDI headquarters, then moves to Europe where he is joined by other operatives to track down the assassin as well as accomplish a second mission of a political nature. One result is involvement with cardinals within the Curia. The assignment is nearly foiled when the WDI cell is uncovered and infiltrated by an element of the target opposing force.