The beginning of modern code-breaking following the creation of a special unit by the British Royal Navy in 1914.

Using rare archive footage and exclusive interviews to document the rise of the code breakers, highlighting the war that involved the brilliant skills of mathematicians and chess players.

Cracking Japanese codes; Japan develops a code-making machine.

The German development of an almost unbreakable cypher machine known as Enigma; the machine became the backbone behind the blitzkrieg.

Efforts made by the code breakers who worked to break German codes and track U-boat movements to protect American and British troops during World War II.