Little Ah Fais an avid and imaginative reader. One night, she reads and reads and unknowingly sinks into a story. There she learns about the secret of the vanished rainbow — the Black Devil has seized it and turned it into seven parti-coloured goblins! Ah Fa decides to break the spell and re-colour the rainbow. Gathering her courage, melodies and goblin pals, Ah Fa gets ready to do battle against the Black Devil...