During World War II, the Axis sent messages to its allies via The Enigma Machine. While America and England intercepted these messages and doing so helped win the war, to this day there are still several unsolved messages that have never been cracked. When a professor attending a garage sale buys a book that has a code hidden inside it, he turns it in to the State Department and gives it to his class to break. That night, assassins murder everyone in his class, except for one grad student, who suddenly finds herself in the center of a conspiracy that can change everything...