Not since the Rosenbergs has an American spy captured the public's imagination. FBI agent Robert Hanssen betrayed his country when he engaged in secret transactions with the KGB.

We trace the origins of this compulsive traitor, beginning in Chicago, where he was born and first became a cop. We explore the devious traits that would later betray Hanssen: his ability to appear to be a religious family man dedicated to truth and honesty, while at the same time, acting out sexual fantasies and destroying the people closest to him.

Hanssen traded the lives of both American and Russian intelligence agents for hundreds of thousands of dollars and sacks of diamonds. In the end, Hanssen was uncovered and arrested on a Sunday morning, after attending mass in a suburban Catholic church.