Scarecrow makes reference to the events of Arkham Knight in one of his coded messages in Arkham city, where he says “Fear will tear Gotham City to shreds.”
This secret requires the use of your cryptographic sequencer as well a lot of spare time, as it is quite complicated to uncover this secret. There is a lot of use of numbers and words, but for the benefit of all of you reading this, I will go straight to the secret. Basically after decoding a lot of numbers and words, a Vigenere cipher is used. A keyword is needed to solve the cipher, and the keyword for the code is “SCARECROW”. Once decoded, it reads: “Fear will tear Gotham City to shreds. After a certain point in the game you will realize that Scarecrow is still alive, and wants revenge on Batman.
