A book that hides a password. A vault that opens when you find it.
Every puzzle in Sudoku with a Secret is an honest sudoku — solvable with a
pencil. But hidden among them are shaded keys. Decode the three words they spell, bring
them here, and three vaults swing open: treasure, lore, and free bonus puzzles —
50, then 100, then 200. No email required. Ever.
Have the book?
Speak your first word at the door above. Each vault you crack drops its rewards and stamps your passport.
