Mac is sent to London by order of the Queen of England to protect the world's finest violin. While guarding the violin alone overnight at the museum, he is ambushed by a mummy—no, a thief in disguise—who steals the violin and slips away. Terrified and shaken from the encounter, Mac cries but refuses to give up his mission. Following the clues left behind by the thief, he heads to Italy with his trusty partner Freddy, since only one of the five legendary violins remains there. The thief is sure to come for it, and Mac plans to catch them in the act! But trouble strikes—Mac is captured by the President of Italy himself. Handcuffed and interrogated, Mac senses something is off, but realizes it too late. While the President keeps Mac occupied, the final violin is stolen. All five of the world's finest violins, the legendary Stradivarius instruments, fall into the hands of Mac's greatest enemy: a KGB agent. Is the KGB agent simply planning to display the violins in a museum to show off to the world? No—hidden behind this heist is a cunning and dangerous plot. The plan is to have the world's greatest musicians perform an addictive piece of music on these priceless violins. Anyone who hears it will find it stuck in their head all day long, unable to think or focus on anything else. Spy Mac fights back with all his might against the KGB agent's clever and flawless scheme, but ends up trapped in a Soviet 'spy prison.' Now, the play button on the cassette player is about to be pressed. Listen closely to find out just what dangerous music is about to play.