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

“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

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

While visiting a ranch near Yellowstone National Park with his parents, Summer, and her parents, Teddy Fitzroy investigates the disappearances of bison and an i

"Superspy middle schooler Ben Ripley races against time and across state lines - traveling by car, train, boat and plane - to track Murray Hill down before Ben'