The land holds the truth the maps will reveal it.Sal, Joe, Francie and Humphrey Santander are mapmakers looking for their father, a famous explorer who disappeared on his last expedition.Their search takes them to Cruxcia, where the people are fighting to protect their land from the all-powerful Grania Trading Company. The Santanders mapping skills may be the missing piece in the Cruxcian race to save the ancient valleyand the key to reuniting their family.A follow-up to the internationally successful The Mapmakers Racethe Santander children are drawn into a communitys rebellion against a despot and use their mapping skills to avert an environmental scam.