Chapter 121 - 123 Summary

Susan realizes there are eight rows of eight, making a perfect square. She recognizes the code as Caesar's box, one of the most basic forms of code writing. With six minutes remaining, the message is revealed. The text reads, "Prime difference between elements responsible for Hiroshima and Nagasaki." Susan explains that it is a puzzle. Susan tells the room that the solution must be a number. Everyone begins to ponder what is the difference in question.

Chapter 121 - 123 Analysis

David had recognized the pattern as Caesar's box. Susan had explained Caesar's box to David when they first started dating. Susan realizes the text forms a square grid and must be read from top to bottom. Tankado had used the answer to a trivia question regarding Hiroshima and Nagasaki as his kill-code. The relevance to Tankado's question lies in his family's history...