The fictional evocation of any milieu should bear a certain responsibility to the question--"What would it be like to live there?"--and no one has a clearer sense of this responsibility than the science-fiction writer Ursula Le Guin; and no one pursues it in more unexpected directions. Malafrena asks something that cannot have occurred to very many of us: what it might have been like to live in a small, quiet principality of the Habsburg Empire during the great 19th-century upwellings of liberalism and nationalism. The country in question is the imaginary "Orsinia," whose history and geography Le Guin has been sketching to herself for a good many years. (See the short-story collection Orsinian Tales, 1976). Her hero in this case is Itale Sorde, an ardent young patriot whose libertarian passions take him from his home in idyllic Val Malafrena to the quiet university city of Solariy, Krasnoy the Orsinian capital, and finally--just before the uprisings of 1830--prison in the wretched factory town of Rakava. His cause and the moral claims of change or continuity are variously perceived by his circle of political writers, the beautiful Krasnoy aristocrat with whom he falls in love, and the rural landowning families of Malafrena. Le Guin brings to their grapplings with large and small bewilderments the qualities that she brings to any story: patience, lucidity, and the capacity to invest the ordinary pleasures of existence with a sort of luminous romanticism. True, what should be real moral exaltation here is sometimes merely facilely achieved sweetness-and-light. But notwithstanding an occasional mistiness around the edges, Malafrena is Le Guin's masterpiece to date--a provocative adventure firmly founded on an unmodish and undeviating nobility of style, of mind, and above all of responsible imagination.