In the fourth installment of the New York Times bestselling Charlie Thorne series—which #1 New York Times bestselling author Chris Grabenstein called “a rea

“Fast-paced, smart, and action-packed...a real page-burner.” —Chris Grabenstein, #1 New York Times bestselling author of the Mr. Lemoncello’s Library se

In this sequel to the New York Times bestselling Charlie Thorne and the Last Equation—which #1 New York Times bestselling author Chris Grabenstein called “a

After tracking down incredible discoveries by Einstein and Darwin, Charlie is back. This time, the great ruler Cleopatra has left behind an extremely valuable a

Charlie Thorne, along with former agents Dante Garcia and Milana Moon, race to find an immensely powerful discovery of Isaac Newton's and face challenges and en