Mystery of the Galilean Grindstone

Thirty-five years after the last Three Investigators novel was published in America, a new series finally arrives, conceived and co-written by Elizabeth Arthur, the daughter of Robert Arthur, the creator of the Three Investigators universe.In the seventh book of a 26-book story arc, it's the start of a new summer. At the end of the previous one, Jupiter invited The Three Investigators' new friend Mallory MacLeod to join them as a Special Consultant. She's also working for Jupiter's aunt and uncle in the Salvage Yard again, so she, Jupiter, Pete, and Bob are all present when Uncle Titus returns from the Napa Valley with a curious sandstone wheel and presents it to Jupiter as a memento of a case The Three Investigators haven't even thought about, much less solved.The wheel appears to be a grindstone, engraved with the birth and death dates of Galilei Galileo, the great Italian inventor and astronomer who had connections to the powerful and wealthy Medici family. So when Uncle Titus suggests that the wheel is linked to rumors of a hidden treasure, The Three Investigators decide to head for the old Victorian "e;calendar house"e; where Uncle Titus found it. Now called Castello Serreno, the house is being renovated as a small hotel owned and operated by Portuguese immigrants who know little about the house's history.As it turns out, both the house and the nearby Franciscan monastery where the boys are staying are thick with Masonic symbols. Soon the boys are counting doors, rooms, and panes of glass, and deciphering two cryptic letters written in pigpen cipher in 1890 by the house's Masonic architect. But things aren't adding up. Is the Italian stonemason Clemente DeLuca as innocent as he appears? Is the man working on a book about calendar houses being honest about his motives? Are the brown cotton robes all the monks wear acting as a disguise for one of them? And does the secret passage hidden behind a wall of Castello Serreno's library have a hidden history?After Mallory joins the boys and tells them what she's discovered about an ancient organization called the Illuminati and its connection to the Masonic Order, the case takes on an added urgency. When the Three Investigators and their Special Consultant find themselves locked in the Tower Room of the castle, they are able to solve the mystery together, but by then it may betoo late. The villains have also discovered the calendar house's secret!In The Mystery of the Galilean Grindstone and the 25 other new Three Investigators books, both old and new fans will find an America as classic as Robert Arthur's novels.