England is in trouble! A priceless violin has been stolen, and there's only one person who can help: Mac B., kid spy. Mac's adventure takes him on a top-secret museum night watch, zip-lining in Italy with his trusty corgi sidekick, and on an undercover mission in the heart of enemy territory. But when he ends up as a captured prisoner, is the mission lost for good?

With fascinating historical facts masterfully sprinkled throughout, the fifth entry in the Mac B., Kid Spy series offers adventure, intrigue, absurdity, and humor.