If there was one thing Lilian Eliot might have said about herself, it was that she knew her own mind. She was not a flighty girl; no one in Boston in 1917 would have said that about her. She wrote her thank-you notes promptly and had some wit which saved her from being too prim. No great misfortune had darkened her eighteen years - in the distance now was the war - but otherwise there was no reason for her life not to be full and prosperous and happy. But how does. happiness come? As her sophisticated aunt says, even a girl who is not an idiot can behave like one, given the right situation and the right boy. When Walter Vail, an enlisted man from New York, descends upon her, dazzling her, and then disappears, Lilian feels she will never marry. But years later she develops an interest in Gilbert Finch, an old Bostonian like herself, solitary and apart, who promises something she understands, and can love. And Walter Vail reappears. Folly is the story of a conventional girl with unconventional stirrings and of the two men in her life who represent different possibilities. In Lilian Eliot's world, from Beacon Hill to summers in Maine to Grand Tours in Europe between the two world wars, it is the choosing of a husband that determines a woman's life. Susan Minot has created a society and a way of life in the tradition of Edith Wharton.