While working at Bletchley Park transcribing decrypted signals from the German Army as it marches into Leningrad, Honey Deschamps begins to receive mysterious packages from Russia containing small pieces of amber that suggest a coded message.

Skilled code-cracker and detective Ruby Redfort has an adventure at sea in which she must crack the case of the Twinford pirates while avoiding a vile sea monster and the evil Count von Viscount.

"Clayton Stumper might be in his twenties, but he dresses like your grandpa and fusses like your aunt. Abandoned at birth on the steps of the Fellowship of Puzzlemakers, he was raised by a group of eccentric enigmatologists and now finds himself among the last survivors of a fading institution. When the esteemed crossword compiler and main maternal presence in Clayton's life, Pippa Allsbrook, passes away, she bestows her final puzzle on him: a promise...

To crack a secret code, Mac follows the clues to France and Japan where he must use his gaming skills and defeat his enemy, the KGB Man.

"The year is 1870. Five years after a series of Dante-inspired killings disrupted Boston, a man is found murdered in the public gardens of London with an enormous stone around his neck etched with a verse from the Divine Comedy. When more mysterious murders erupt across the city, all in the style of the punishments Dante memorialized in Purgatory, poet Christina Rossetti fears her brother, the Dante-obsessed artist and writer Gabriel Rossetti, will...

"In the wake of her parents' mysterious disappearance, a society girl discovers her dilettante father and flighty mother were leading double lives as government spies. With the help of her uncle and mentor, she determines to continue her parents' work-a decision that takes her from the ballrooms of London to the fox hunts and regattas and soirees of high society, chasing down artfully hidden clues while trying to keep her mission a secret from her...

Kit Sutherland moves to Washington, DC to work as an codebreaker at Arlington Hall, but when she stumbles onto a bloody homicide scene, she joins forces with other girl codebreakers to find the man killing Government girls.

The CIA forces twelve-year-old Charlotte "Charlie" Thorne, a rebellious genius, to use her code-breaking skills on an epic global chase to locate Einstein's last equation before dangerous agents discover it and unlock the solution to harnessing energy.--

In 1666, after four months away, friends Christopher Rowe, Tom, and Sally return to London triumphantly but, guided by coded riddles, face a conspiracy that threatens Christopher, as well as the King himself.

"PhDeath" is a fast-paced thriller set in a major university in a major city on a square. The faculty finds itself in deadly intellectual combat with the anonymous Puzzler. Along with teams of U.S. Military Intelligence and the city's top detective and aided by the Puzzle Master of The New York Times, their collective brains are no match for the Puzzler's perverse talents.-- In a major university in a major city, the faculty finds itself in deadly...