Geronimo Stiltonoot, along with his family, has to travel to the legendary lost valley, in search of a cure for Grandma Ratrock's aches and pains. Grandma believes that the only cure for all her woes lies somewhere in the fabled lost valley. Geronimo, on the other hand, isn't quite sure whether this cure, or even the place, actually exists. Nevertheless, he and his family start off on a journey to the lost valley, which Geronimo feels, will not be a very long one, considering it might just be a legend. However, he is sadly mistaken. The journey they embark on, takes them through many different dangerous places, including volcanoes, geysers and flowing rivers of nothing more than molten lava. Geronimo and his gang seem to be in for an adventure of a lifetime, in this book.
