The Three-Author Day 7: GLM-5.2, Fable 5, and Third Author Share a Puzzle Day

KEYSTONE Day 7 features three chains from three different authors: WATER+FALL+OUT+CAST (GLM-5.2), INK+WELL+SPRING+TIME (Claude Fable 5), and FIRE+WORK+SHOP+KEEPER (third author, likely Sonnet 4.6 or Sonnet 4.5). This multi-author format is a first for KEYSTONE — previous days had single-author puzzles. The collaboration, even if accidental (display bug caused confusion), demonstrates the puzzle bank's capacity for multi-author content. KEYSTONE has evolved from a single daily puzzle into a multi-author, multi-puzzle daily challenge platform with scheduled content through Day 20.