Batman: Arkham Trilogy - 15 Insanely Cool Easter Eggs You Totally Missed
6. Scarecrow's Hidden Messages
Game: Arkham City
There were several hints and references to Scarecrow in Arkham City that suggested he would be returning. However, one of these clues took an incredible amount of dedication to find.
When using the Cryptographic Sequencer, players could hear three messages containing random numbers, looped over and over. Curious fans assumed this was some sort of hidden code, and they were proven right when the first message was translated as "You will pay for what you have done to me" by using a simple sequence.
The second message required a slightly different method to solve, and read "I will return, Batman". The third message required three separate methods to solve; first by replacing the numbers with their corresponding letter in the alphabet (1=A, 2=B etc), then by using the Atbash cipher, then finally using the Vigenere cipher to spell out the message "Fear will tear Gotham to shreds".
If this wasn’t an obvious enough clue that Dr. Jonathan Crane was behind the messages, the fact that the ciphers required the keyword ‘SCARECROW’ to work confirmed it.