This companion site to the Nova episode "Decoding Nazi Secrets," broadcast this month on PBS, provides substantial essays on codebreaking and making, encryption on the Web, the mechanics of the Nazi's encoder Enigma, the personalities and genius of the men who cracked its code, and opportunities for users to code their own messages or participate in a codecracking contest (November 5-19). Additional resources and a teacher's guide are also provided. We can imagine the site both generating enthusiasm among high school students and helping them to develop valuable analytical skills.