Throughout 1942, German U-boats sank hundreds of American ships in the Atlantic Ocean, effectively cutting the supply line to embattled ally England. In desperation, the U.S. Navy turned to the National Cash Register Company in Dayton, OH to design and build code-breaking machines. The high-priority and highly classified project involved hundreds of civilians, Naval officers, and one engineer of German descent-Joseph Desch, whose insight and technical ability helped break the complex Enigma code. Though Desch remained faithful to his pledge of secrecy regarding the Dayton project until his death in 1987, he left behind mysterious papers and clues for his daughter to unravel.