One of the great intellectual undertakings of our time has been John Richardson's multivolume biography of Pablo Picasso. Richardson, who knew the artist personally, has parsed the issues of Picasso's rich life and nimble art more thoroughly than anyone before him. Eleven years after Vol. II, the third installment arrives in November. A Life of Picasso: The Triumphant Years, 1917-1932 (Knopf; 608 pages), picks up the story with the 35-year-old Picasso's courtship of his first wife, the Russian ballerina Olga Khokhlova. For a time, he attempts a life of bourgeois propriety at home and neoclassicism in his art (which he alternates with continuing exercises in Cubism). But in 1927, the restless and ever tumescent artist meets and beds 17-year-old Marie-Thérèse Walter. Their passionate affair throws his marriage into turmoil, even as it floods his art with lush new signs for pleasure and fulfillment. Richardson leads us through the grand story with energy, wit and authority.