This is the humorous story of how Rosie and the neighbourhood children find fun and wonderful ways to fill their days: One day there is a sign on Rosie's door that reads, 'If you want to know a secret, knock three times.' Rosie's secret is that today she is not Rosie, today she is Alinda, the lovely lady singer and together with her friend Kathy, alias Cha-Charoo the Arabian dancing girl, they put on a great musical show for Dolly, Pudgy and Sal. Until, that is, they are interrupted by Lenny who today is a fireman and they all dash off to help him put out fires. Soon there is another sign on Rosie's door which leads the gang to her front steps where they all sit quietly waiting for the Magic Man, who is coming to tell them what to do. When he finally arrives he tells them all to be firecrackers , so they Boom and Whizz and Fizz until it is time to go home for tea.