I wondered what the sign in Paris meant and how it applied to history. How often in history does "one train may be hiding another one"? Naziism in World War II was just hiding an even greater conflict of Communism over the next 40 years. War with Mexico was hiding the upcoming Civil War. Agincourt seemed a great victory for good King Hank, but just clouded the loss that was coming with Henry 6. Other applications?