The final instalment of the documentary opens in Salisbury with the poisoning of Sergei Skripal and his daughter, before tracking back to see how Vladimir Putin's return to the presidency in 2012 after a four-year absence was greeted by furious protests and accusations of corruption, as well as American sanctions. The programme also looks at Putin's decision to annex Crimea and launch a war in eastern Ukraine and Russia's interference in politics on both sides of the Atlantic and in the Middle East.