Oscar sits at his bedroom window, dreaming of a place high up, above the clouds and below the stars! This is the best place for his dreams. But there's no time for Oscar to dream. He's going on holiday with mum and dad and all is chaos and confusion. Then, quite before he realises what has happened, he is alone and his parents have disappeared. What is he to do? And then he hears a voice in the desert -- it is a little cloud called Hoo, as lost and lonely as Oscar. Together, the boy and the cloud set out to find Oscar's parents, and become inseparable friends on their journey.