Geronimo Stilton"s ancient ancestor Geronimo Stiltonoot is back in another prehistoric adventure! Geronimo Stiltonoot and his family are off to find a cure for Grandma Ratrock"s aches and pains. She"s heard that a remedy hides in a legendary valley, and Geronimo isn"t even sure it exists. Little does he know that getting there will be an adventure among geysers, volcanoes, and rivers of molten lava!