Code Girls: The Untold Story of the American Women Code Breakers of World War II

by Liza Mundy

Together the code breakers were able to reconstruct Yamamoto’s precise itinerary, which called for a day of hops between Japanese bases in the Solomon Islands and New Britain. Their translation concluded that the commander would “depart RR (Rabaul) at 0600 in a medium attack plane escorted by six fighters; arrive RXZ (Ballale) at 0800”; depart at 1100 and land at RXP (Buin) at 1110; leave there at 1400 and return to Rabaul at 1540, traveling by plane and, at one point, minesweeper. He would be conducting an inspection tour and visiting the sick and wounded. It was an extraordinary moment. The Americans knew exactly where the enemy’s most valuable—and irreplaceable—naval commander would be, and when. Yamamoto was known for punctuality. Far above the pay grade of those working additive recovery, Nimitz and other top war officials decided Yamamoto would be shot down. It was not a light decision, assassinating an enemy commander, but they made it. The itinerary, as one memo later put it, signed the admiral’s “death warrant.”