When Arthur uncovers a distress call sent from Minimoys, the invisible people who live in his own back yard, he knows that once again, he must embark on a great adventure to battle against the evil Maltazard and save Princess Selenia. Little does he know that this is an evil trick by his arch nemesis to reverse the magic of transformation to become a giant when Arthur passes into the Minimoy's world. Now at less than half an inch tall, Arthur must save his own world from a giant evil Maltazard. Will this little hero have what it takes?