Walking through the streets of his hometown of Vienna, Lucas Grassi sees an archduke's coach, with the archduke's faithful dog running alongside. He wishes he could be the dog and be free from his everyday life. Then his wish comes true: Lucas does become the dog. Every other day he switches from his normal body to that of the archduke's canine companion. Soon he learns the dog is treated badly and the archduke is not a nice man. Lucas decides he'll do anything to reverse his wish... if only he knew what to do!