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

Rare archive footage and exclusive interviews document the rise of the code-breakers, who fight using the brilliant skills of mathematicians and chess players.

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

The Battle of Midway, fought in World War II, took place on June 5, 1942. The United States Navy defeated a Japanese attack against Midway Atoll, marking a turning point in the war in the Pacific theater, The American code breakers worked to decrypt the complex Japanese ciphers. It was a game of chess to anticipate the enemy's next move.

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 in order to protect American and British troops during World War II.