US intelligence intercepts a coded message from Tokyo to the Imperial Japanese Consulate in Hawaii. However, the interceptors do not have any decryption capabilities as MAGIC (the American military code breaking operation) is a closely guarded secret. Accordingly, the message along with others, is marked for dispatch by air courier to Washington. Unfortunately, the weather is dreadful and the weekly flight scheduled for the 26th is cancelled. So the still coded message, along with the others, is placed on a ship bound for the West Coast. It eventually arrives in DC on October 6, 1941 and is placed in que for decoding. Several days later, the message is decoded.
It directs the consulate to divide Pearl Harbor into zones and report the number and types of ships in each zone, with names where possible. This is referred up the chain of command as possibly significant. But the intelligence brass conclude it is routine. Diplomats are always keeping an eye on the military activities of their host countries. Other intercepted messages show that similar orders have been sent to Japanese diplomatic outposts in the Philippines, the Dutch East Indies, Australia, and the British colonies at Singapore and Hong Kong.
Nothing to worry about here.