The Magic machines had intercepted an unusual message sent via the Purple codes, and it immediately crossed the desks of everyone in Washington authorized to receive it. It was an oddly detailed set of instructions from the Japanese foreign ministry to its consulate in Honolulu. The instructions called for the entire area in and around Pearl Harbor to be laid out in a series of grid lines, as though a checkerboard was to be superimposed over a map. The instructions also called for the consulate to designate the types and classes of the warships anchored in the harbor.
