PUZZLESECRET
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The Author & Lore

Behind the Vaults

A book that hides a password. A web vault that opens when you find it. Here is the story of how Sudoku with a Secret was born.

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

The Keeper's Vault

200 Sudoku Puzzles · 3-Act Cipher Progression · Available Now

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VOL. II

The Corsair's Chart

Pirate cipher maps, buried coordinates, and sea-shanty word grids.

In Writing
VOL. III

The Lost Love Letters

Victorian wax-sealed cipher correspondence and hidden acrostics.

Concept
VOL. IV

The Silent Signal

Cold-war bunker telegraph codes and frequency-shift Sudokus.

Concept
VOL. V

The Hollow Oak

Ancient druidic runic wheel ciphers and botanical puzzle maps.

Concept