El Cuarto Aprendiz / The Fourth Apprentice - Erin Hunter - Bog

Four warrior clans have inhabited the land around the lake as equals for many moons, until a prophecy foretells that three ThunderClan cats will hold the power of the stars in their paws. Glayo and Leonado know that they are two of the chosen ones. These two brothers must wait for a signal from StarClan to discover the identity of the third. Meanwhile, Little Turtledove and Little Spinel, relatives of the great leader Firestar, are ready to become ThunderClan apprentices. After a disturbing dream, one of the sisters slowly begins to realize that her supernatural abilities are more powerful than any other cat.