Prince Jacob ignores his parents' warnings and plays in the Forbidden Forest. He finds the magical seal that his father, the Jade Emperor, has used to contain the Dark Forces. When the prince touches the seal it shatters, and the twelve diamonds and beautiful jade in their centre are scattered across the world. Once again evil has taken over the world. Without the seal the Jade Emperor has no way of containing the Dark Forces, so he has no choice but to destroy Earth. Feeling responsible, Prince Jacob begs his father for a chance to find the diamonds and the jade, restore the magical seal and banish the Dark Forces. The Jade Emperor agrees, but he knows that his son cannot do this alone. Since the evil of the Dark Forces affects the human race only and not the animals, the Jade Emperor organises a Great Race across the Trial River to find the bravest animals on Earth to help Prince Jacob in his quest to save Earth. Leading the charge is the legendary Mus Mouse, whose task it is to find the pink diamond. She makes her way to Rome, where she confronts the full might of the Dark Forces. She must escape the city alive if the quest is to succeed.