David Olusoga traces the lives of residents of two apartment blocks - one in London and one in Berlin - during the Second World War to reveal what life was like for citizens during the deadliest conflict in world history. The historian begins by looking at the situations of the building owners back in the 1920s just after the First World War, with both owners being former soldiers the impact of the war still had its hold over them but the economic chaos in Germany is driving the country to support a new political party