Who is Geronimo Stilton? That's me! I run a newspaper but my true passion is writing tales of adventure. Here is New Mouse City, the capital of Mouse Island, My books are all bestsellers!! My stories are full of fun tastier than Swiss cheese and tangier than extra-sharp cheddar. They are whisker-licking good stories and that's a promise! Do you like solving mysteries? I do! So when my sister-Thea-heard that there was a secret hidden in Mouse Island's most famous painting the Mona Mousa. I knew we had to crack the code! We began to Investigate and soon as we were following a trail of clues that led us below the streets of the New Mouse City. There we made the most fabulous discovery.