Mac Undercover (Mac B, Kid Spy #1), Paperback/Mac Barnett

Before Mac Barnett was an author, he was a kid. And while he was a kid, he was a spy. The precious Crown Jewels have been stolen, and there's only one person who can help the Queen of England: her newest secret agent, Mac B. Mac travels around the globe in search of the stolen treasure...but will he find it in time?