As of the middle of 1941, then, this machine existed in this vault, here at Station Hypo. It existed because Schoen had built it. The machine perfectly decrypted every Indigo message that the intercept stations picked up, and was, therefore, necessarily an exact functional duplication of the Nipponese Indigo code machine, though neither Schoen nor any other American had ever laid eyes on one. Schoen had built the thing simply by looking at those great big long lists of essentially random numbers, and using some process of induction to figure it out. Somewhere along the line he had become totally debilitated psychologically, and begun to suffer nervous breakdowns at the rate of about one every week or two.