Leo Flower got his name in a Greenwich Village orphanage because he loved to listen to Mayor Fiorello Laguardia, New York's "Little Flower," read the funny papers on the radio. When Leo is twelve, he is adopted by a priest and his sister and raised as their own. They love and support him throughout his schooling and his time in the military.

After leaving the army, Leo becomes a cop and eventually a lieutenant. Time passes, and he's sixty, drifting in a dull but comfortable routine. That existence comes crashing down, however, when his adoptive parents are murdered. With seething vengeance, Leo hunts for their killer. His search is interrupted when he is transferred to an elite unit and assigned to develop a plan to stop the assassination of the Pope during his visit to the United Nations. As his search for the murderer continues, Leo puts his plan to save the Pope into action with the help of a street thug, an old gangster, a famed French actress, a doorman, and the Catholic Church.

The search for one thing often leads to the discovery of another; so it is with Leo Flower-a man seeking a killer and finding instead something he never expected.