Helene Cooper is ""Congo,"" a descendant of two Liberian dynasties -- traced back to the first ship of freemen that set sail from New York in 1820 to found Monrovia. Helene grew up at Sugar Beach, a twenty-two-room mansion by the sea. Her childhood was filled with servants, flashy cars, a villa in Spain, and a farmhouse up-country. It was also an African childhood, filled with knock foot games and hot pepper soup, heartmen and neegee. When Helene was eight, the Coopers took in a foster child -- a common custom among the Liberian elite. Eunice, a Bassa girl, suddenly became known as ""Mrs. Cooper's daughter."" For years the Cooper daughters -- Helene, her sister Marlene, and Eunice -- blissfully enjoyed the trappings of wealth and advantage. But Liberia was like an unwatched pot of water left boiling on the stove. And on April 12, 1980, a group of soldiers staged a coup d'