Geronimo Stilton travels through time in order to defend history from his arch nemeses, the Pirate Cats. These devious felines plan to travelback in time in order to change history to make them supreme rulers of Mouse Island! In his first time-traveling adventure, Geronimo and co. join Christopher Columbus on his voyage from Italy to America in 1492 in order to stop the Pirate cats and save all of the mice on Mouse Island.