In his fictional Falls, North Carolina-a watchful zone of stifling mores-Allan Gurganus's fond and comical characters risk everything to protect their improbable hopes from prejudice, poverty, betrayal. Seeking warmth and true connection, they shield themselves and loved ones while creating a rarely-glimpsed world of valor, minor grandeur, side-street heroics. Muriel Fraser, a poor Scottish-born spinster, is the subject of a John Singer Sargent portrait...