It's a story of fiction and fantasy.One brother and one sister went out to play and accidentally fell into a pit..that's where the story starts. They enter into a country named Rebbica. There they have to find a stone named Heart of Rebbica, but it was not a easy task. The stone was present in a cave. There they find out their father, who told them that the cave is guarded by an army of thousands of trolls and goblins, but still they took the Heart of Rebbica . They now had to take it to the queen of Rebbica. After giving it to queen of Rebbica she granted them a boon to transport them to their home with their father. That's how story ends, to find out how many adventures they did, read the book.