The Mystery of the Galilean Grindstone (New Three Investigators)

The Salvage Yard is still there. So is the secret headquarters. And so are the Three Investigators—smarter than ever, a little older, and ready for their most challenging cases yet. Conceived and co-written by Elizabeth Arthur, the daughter of Robert Arthur, the creator of the Three Investigators universe, this exciting reboot of the classic series takes its iconic characters into a new age. They return reimagined, reinvigorated, and more relevant than ever. In the seventh book of a 26-book story arc, the summer is beginning with an unusual challenge for The Three Investigators. At the end of the previous summer, Jupiter invited their new friend Mallory MacLeod to join the team as a Special Consultant. She's also been helping out at the Salvage Yard, so she, Jupiter, Pete, and Bob are all present when Uncle Titus returns from the Napa Valley with an intriguing artifact—a curious sandstone wheel. The wheel appears to be a grindstone, engraved with the birth and death dates of Galileo Galilei, the brilliant Italian inventor and astronomer with ties to the powerful Medici family.