The story begins with the describing a forgotten door - a gump on an abandoned railway Platform 13 at Kings Cross Station which is the entrance to a magical kingdom - an Island, where humans live together sensibly and peacefully with mermaids, ogres, and other wonderful creatures and among others also lovable animals known as mistmakers. This door opens for nine days every nine years and during those nine days, beings are free to come and go between our world and a magical Island. When the infant prince of the Island is kidnapped to our world by the unpleasant Mrs. Trottle, a strange band of rescuers is chosen nine years later to bring him back. This band consists of a wizard, an ogre, a fey and a young hag. At first the rescuers are delighted to meet Ben, a sweet boy who could be the prince in spite of his lowly status in the Trottle house. But it soon becomes apparent that the real prince must be Raymond, the Trottles' rather odious, spoiled son. Raymond, however, has no interest in leaving his pampered life for a mystical island. When Raymond blabbed to Mrs. Trottle that someone wants to take him on some Island, Mrs. Trottle takes him and leave. Rescuers find them after few days. When their plan fails and Ben is hurt, they decide to go home to the Island without Raymond. Meanwhile on the Island everybody is waiting and there is not much time to ´Closing´. King and a Queen send harpies to bring the prince back. At last day everybody is on the harbor waiting for rescuers and their stolen prince. Among others King and Queen. A wizard, ogre and a fey are coming barehanded as the first. Wake of rescuers harpies are flying in, carrying a bag with Raymond. As the last a hag and Ben are coming. Ben runs to a King and a Queen and throws himself into their arms. He is the real prince and Raymond is taken back to our world. Ben got a letter from his grandmother Nanny Brown who was with Mrs. Trottle. In the letter there was written that he was kidnapped by Mrs. Trottle. When she found out that she is expecting baby of her own, she wanted to send Ben away. Nanny Brown did not let her.