1942年四月，第二次世界大战期间，大西洋，史上规模最大的海军战役正在进行中......一艘美国潜艇 S-33 秘密出航，船员们的使命是：从一艘德国潜艇上获取德军最先进的译码设备。只有这样，盟军才能及时发觉德军的打击行动以减小损失！如果一切顺利进行，船员们将能够在敌方毫无所觉的情况下摧毁敌方的潜艇，并得到他们所需要的东西。但是，一切事情都会这么顺利吗？他们要面对的不仅是敌人，还要与有限的时间竞争，更要克服潜藏于内心深处的恐惧......

During the worst days of World War II, the British government asks the mathematician Alan Turing to unravel the mysteries of the German Enigma encryption machine, an impossible task to accomplish without the invaluable information that Hans-Thilo Schmidt, a disenchanted but greedy German citizen, had been handing over to the French secret services since 1931.

A thought provoking documentary feature film providing a comprehensive exploration of the evolution of signals intelligence over the past century. Whether you're intrigued by the secretive world of intelligence agencies or concerned about the implications of digital surveillance, this film will leave you with a deeper understanding of the role signals intelligence plays in society.