Though I just plucked it from my bookshelf, it's been a good many decades since I read The Man in the High Castle, so I had to crib (more than a a bit!) from its Wikipedia entry:
The Man in the High Castle is an alternative history novel by Philip K. Dick, first published in 1962, which imagines a world in which the Axis Powers won World War II. The story occurs in 1962, fifteen years after the end of the war in 1947, and depicts the life of several characters living under Imperial Japan or Nazi Germany as they rule a partitioned United States. The eponymous character is the mysterious author of a novel-within-the-novel entitled The Grasshopper Lies Heavy, a subversive alternative history of the war in which the Allied Powers are victorious.
In the alternative history imagined in The Man in the High Castle, Giuseppe Zangara assassinates President-elect Franklin D. Roosevelt in 1933, resulting in the continuation of the Great Depression and the policy of United States non-interventionism at the start of World War II in 1939. American inaction allows Nazi Germany to conquer and annex continental Europe and the Soviet Union into the Reich. The exterminations of the Jews, the Romani, the Jehovah's Witnesses, the Slavs, and all other peoples whom the Nazis considered subhuman ensued. The Axis powers then jointly conquered Africa, and still compete for the control of South America in 1962. Imperial Japan won the war in the Pacific and invaded the West Coast of the United States, while Nazi Germany invaded the East Coast; the surrender of the Allies ended World War II in 1947.
The novel won science fiction's most prestigious award, the Hugo, in 1963, the year after it was published. As with most stories from Philip K. Dick, it's a bit eclectic. But it's a rollicking good read featuring three very intriguing sub-plots. As one of Dick's contemporaries, Avram Davidson, put it: "It's all here — extrapolation, suspense, action, art, philosophy, plot, [and] character".
And now, on to tonight's puzzle. Below are links to an on-line board to help you work the puzzle, and the solution. But don't peek at the answer until you've made an honest attempt to solve the puzzle, or you'll spoil the fun!
On-line board
Solution