PAGE ONE
I was not always a keeper of vaults. I was a maker of puzzles — and a poor one — in a room exactly this size.
The Keeper
The Keeper's Story
A man set two hundred grids and hid a second puzzle inside them. He does not give his name. What he gives, he gives in pages, and only to the ones who look.
The pages begin in a paperback: Sudoku with a Secret, Volume 1, $14.99. Get the book on Amazon (opens in a new tab) Already have it? Speak your first word at the door
The page he did not hide
Pages in his hand
“Nine pages. Three rooms. Three in each. I will say no more than that.”
You hold none of his pages yet.
Eight more pages lie about his vault, on the floor, where nobody looks. They are found, not bought, and the first room is open to anyone who knocks.
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PAGE TWO
Not yet found. Page two is still in the vault.
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PAGE THREE
Not yet found. Page three is still in the vault.
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PAGE FOUR
Not yet found. Page four is still in the vault.
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PAGE FIVE
Not yet found. Page five is still in the vault.
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PAGE SIX
Not yet found. Page six is still in the vault.
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PAGE SEVEN
Not yet found. Page seven is still in the vault.
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PAGE EIGHT
Not yet found. Page eight is still in the vault.
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PAGE NINE
Not yet found. Page nine is still in the vault.
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THE LAST PAGE
Written for whoever finds all nine.
What he said in his study
From his notebook
Left open on his desk. Six leaves: how he set the grids, and what comes next.
THE KEEPER’S NOTEBOOK
Notes I kept while setting two hundred grids. Take what is useful; leave the rest for the next reader.
Turn the page.
I · SPOTTING A KEY
Some of my grids carry one shaded square. It is never a given — it sits empty and waits for you to solve it honestly. The digit that lands in the shade is the key.
Copy it to the Vault Door Tally (page 210) before you forget. The plates that turn digits into letters are in the back of the book, pages 213 to 215.
II · SCANNING
Pick a digit that already appears often. Run its rows and columns across the grid like beams of light. Where the beams leave exactly one dark cell in a box, that digit lives there.
It is the fastest way through my easy grids, and it still works on the hard ones.
III · THE LONELY CANDIDATE
When a cell has only one digit left that could fit, write it and move on. When a digit has only one cell left in a row, a column or a box, it goes there — even if that cell could take others.
The first rule looks at a cell. The second looks at a digit. Learn to switch between them.
IV · PAIRS
Two cells in the same unit that share the same two candidates own those two digits between them. Strike both digits from every other cell in that unit.
Pencil marks are not cheating. They are how I set the grids in the first place.
V · WHAT COMES NEXT
The Corsair’s Chart. Volume II. Still being drawn, and it will not be kinder than this one.
When it is finished, it will be where the first one was.
“Some of it I will tell you when the next chart is drawn. Some of it I will not.”
Out of character
About Dan Herlehy
Creator & Author of Sudoku with a Secret
Dan Herlehy created PuzzleSecret to combine the timeless joy of classic paper-and-pencil Sudoku with the thrilling discovery of an escape room or treasure hunt.
Instead of superficial gimmicks or low-quality AI grids, every puzzle in Sudoku with a Secret is an honest, hand-graded Sudoku puzzle. The secret cipher mechanics are built seamlessly into the book's structure—meaning solving the book unlocks a living digital vault of bonus puzzles and rewards.
The 5-Volume Series Roadmap
Five books. Five distinct glowing seams. Five unique secret mechanics.
VOL. I
VOL. II
The Corsair's Chart
Pirate cipher maps, buried coordinates, and sea-shanty word grids.
In WritingVOL. III
The Lost Love Letters
Victorian wax-sealed cipher correspondence and hidden messages.
ConceptVOL. IV
The Silent Signal
Cold-war bunker telegraph codes and frequency-shift Sudokus.
ConceptVOL. V
The Hollow Oak
Ancient druidic runic wheel ciphers and botanical puzzle maps.
Concept