From the narrow streets of London to the unexplored tropical rainforests of Africa, to the misty hills of South America, Alvin and Jett get sucked into a fantastic hunt for the world's largest vivid yellow diamond. Along the way they unearth the ancient secrets of its mystical past and discover its links to a hidden treasure and unimaginable wealth that had once sealed the fate of a mighty kingdom. Legends come to life from within the burning heart of the diamond as Alvin and Jett face hostile situations and search remote corners of the world while competing against some of the most powerful men from the pages of history.