Stalin. Step to the right

This book is dedicated to one of the most dramatic periods of our history, which predetermined the fate of not only the USSR, but also modern Russia. The question was resolved whether or not to be accelerated industrialization (which we still use the fruits of it) The direct clash included the largest clans in the leadership of the USSR - conditional "right -wing" (Bukharin, Rykov and Tomsk) conditional "left" (Trotsky, Zinoviev, Kamenev, Sokolnikov and Krupskaya) and a group of Stalin, which conducted its own game. At the XIV Party Congress, the relations between the members of the Politburo crossed the permissible framework, the discussion became a form of information of old accounts. It is this fight that will lead Trotsky to the exile and the “ice ax”, Kamenev, Zinoviev and Bukharin to death, and Stalin to absolute power. Why did Stalin unexpectedly supported the "right -wing" in those days, although he criticized them more recently? What was the purpose of this strange "step to the right ”? What did this led to?