The Rat King — Steve Elliott

It has proven to be an interesting time for Jack and Justin. First of all, they discover a secret door, which leads them to a whole new world, inhabited by talking animals. Then they form a friendship with Whiskers, a telepathic tiger. On their second visit, they become entangled with a horde of rats, who appear to have ambitions to rule the world. But there are further mysteries to be solved. They find something resembling a key, but what does it do and what does it open? Rally, the Court Magician, tells them of a prophecy which describes a series of keys which can open a portal, leading to the world of the original inhabitants and creators of the animal world. Jack and Justin decide to pursue this prophecy, but they find themselves caught up in a terrifying adventure which threatens their very lives. It introduces them to a truly horrifying and deadly enemy, who is also after the keys.