Geronimo Stilton Secret Agent starts with Geronimo enjoying the dawn of a new day with a pot of hot cheddar, his favorite kind of breakfast. As he looks out of the window, he sees a strange rodent wearing dark sunglasses. Soon, Geronimo finds that the stranger is following him wherever he goes. At last, Geronimo confronts him and asks him what he wants. To his sheer amazement, he finds that it is his childhood friend Kornelius Von Kickpaw, who is now a secret agent. Kornelius takes Geronimo to his family mansion and introduces him to his beautiful sister Veronica. Cornelius has a surprising proposition for Geronimo. He asks his friend to become a secret agent too. The surprised Geronimo agrees, though he doesn’t have even a hazy idea about what it takes to be a secret agent. The decision proves lucky for him eventually as he is able to get Cornelius’s help later in a personal matter. Geronimo has lost an important document relating to The Rodent’s Gazette that his grandfather gave to him. If it is not recovered,soon, he might lose the newspaper. Geronimo Stilton initially decides that he will find the document on his own, without asking any of his friends for help. He tries to find clues to trace it and the search leads him to the most disreputable areas of New Mouse City, dirty, filthy and littered with garbage. Geronimo Stilton Secret Agent also contains information that educates the readers. As Geronimo continues his bungling search, the readers also get to learn about garbage disposal, hygiene and recycling. The book has received good reviews since it was published in 2008.