In a remote hill town in Italy, a renowned scientist enters the confessional. A dying man, he pours out the secret that has consumed his life for years - a sin of such magnitude that the shocked priest refuses him absolution.

In a suburb of Washington DC, Joe Lassiter's only sister and her young son have been killed in a sudden fire that engulfs their home. The police believe it was arson; they soon discover that mother and child were brutally murdered before the blaze was set.

As Lassiter tries to find out why they were killed, he comes to believe others may have been murdered in similar fashion. And still more people may die if he cannot discover the elusive connection that links the innocent victims together.