John Richardson opens the final (fourth) volume of his magisterial biography of Pablo Picasso with the artist in more than usual disarray. The year is 1933 and, while his celebrity and his wealth are unassailable, Picasso’s marriage to the Russian ballerina Olga Khokhlova has entered its bitter endgame. Meanwhile, his relationship with maîtresse-en-titre Marie-Thérèse Walter, tucked away in the country, is beginning to pall even before it has properly hit its stride. Waiting in the wings is Dora Maar, the surrealist photographer who will dominate Picasso’s life, mostly painfully, for the next eight years.