Reply To: 9A/9B
9A was encrypted with a Vigenere cipher and then reversed. To decrypt it, first reverse the text and then decrypt Vigenere with the keyword TRAITOR.
9B was a 5×5 playfair cipher similar to 8B however with one of the rules changed. The grid can be found in case file 9.5. The rule change was that if 2 letters were in the same column as each other, the decrypted letters were the ones to the RIGHT not below as usual. Madness did a great job at explaining how the playfair works (and how to modify it) in the ‘Let’s talk about the Playfair cipher’ thread.
I hope this helps.