Hello, mouse friends! Join me, Geronimo Stilton, in solving this whisker-licking-good mystery. Find clues along with me as you read. Together, we'll be super-squeaky investigators!A mysterious monster has been sighted in a lake on Mouse Island. I knew I was just the rodent to investigate! But when I travelled to the lake with my family to try to photograph the monster everything started to go wrong. Could I figure out this creature's secret? Mouldy mozzarella, it was an adventure!A mini mystery in mini format!