Thirty years old when he won a startling upset victory in his race for U.S. Senator, Mark Coffin was bright, handsome, engagingly idealistic. He believed that honesty and decency would see him through a long and successful political career. His wife, a senator's daughter, should have prepared him better, but even Linda Coffin could not have imagined the intensity of pressure when her husband refused to play by Washington's time-honored rules, or the viciousness when he committed the most unpardonable sin of all: Mark Coffin got caught - with another woman.