The Man in the High Castle is an alternative history novel set approximately fifteen years after the end of the Second World War, in a world in which the Axis powers emerge victorious. The point at which the novel diverges from true history is 1933, when Guiseppe "Joe" Zangara succeeds in his attempt to assassinate President Franklin D. Roosevelt. This leads to a chain reaction of events which leads to the U.S. become weak and isolationist and unable to defeat the Nazis when the time comes.
It uses the device of a novel-within-a-novel to describe yet another fictional reality (in a book titled The Grasshopper Lies Heavy), in which the Allies win the war, but their victory differs from...