An anonymous villain has kidnapped Jerry! Now the villain is sending Sam, Alex, and Clover on a scavenger hunt for clues to their boss's secret location. The spies endure one dangerous task after another only to discover that the clues are written in a secret code! Can the spies decode the messages and get to Jerry before it's too late? Readers can use the detachable cardboard decoder to help decode the messages with the spies.