 Complete the following phrase:  After the October Revolution, about which he felt apprehension, he spent some time wandering around Russia in the Luga district, Smolensk, Kostroma, and Crimea. He visited the city of Ostashkov, where he began work on his novel Ugryum-reka Ugryum River or Grim River, a historical novel about wealthy Siberian merchants at the turn of the century which was published in two volumes in 1933. His first novel to be published, however, was Vataga The gang, 1923. From 1927 he lived in Detskoye Selo. For the last seven years of his life he worked on the historical epic Yemelyan Pugachev , a colorful panorama of the 18th-century Cossack and peasant 