Tom is a toymaker's apprentice who is fascinated by all things clockwork. His unpleasant master, who wants him just to paint puppets al day, throws him out of the workshop. Without a job, Tom sees a post advertised on the town noticeboard to rid the kingdom of Flamethrottle, a ferocious dragon. With his friend Lizzie, Tom builds a clockwork dragon and they set out to defeat Flamethrottle. The two children wind up in a thrilling adventure.... and the dastardly dragon finally meets his match.