We unconsciously at least once a day using different secret codes. There is a constant struggle between those who plucks his secrets and those who are trying to find out these secrets. This confrontation goes more than one century. Cracked codes, thereby changing the course of history sometimes. Queen of Scotland, Mary Stuart was executed, when it was deciphered its message to the plot. The telegram from Arthur Zimmerman intercepted, forced America to get involved in the First World War. Zodiac, which kept at bay in San Francisco, went on to kill, from the fact that nobody has been able to explain to his encrypted message. This movie about codes that have changed history.