DR ! EAT A TORPEDO ( Z13)

A Curious Connection Between the Z13 and the Z340 Knight's Move A video I recently watched about a Z13 solution proposed by Mr. Garlicks really caught my attention. His proposed plaintext is DR EAT A TORPEDO—you can check out the full breakdown in the video over on Dave’s channel. Looking closely at the cipher setup, I noticed something interesting. As is well known, the cipher's initial sequence runs from A to M. I decided to experiment by continuing the alphabetical sequence from N to Z in reverse order. To my surprise, bingo! The exact letters needed for the proposed solution appeared.

Even more fascinating is what happens when you apply the knight's move—the same transposition pattern famously used to solve the Z340. Applying that exact technique reveals the letters T and R right in place.