Eleven year-old twins, Demi and Semmy hear something familiar behind the Con. where they learn music. This sound is haunting them but who or what is making it? Can their great-grandmother help solve the mystery? Or do they have to be brave and face this unique musician on their own? No wonder he or she is hiding because it's impossible for this particular musician to be in Australia at all. If the twins are brave, what will happen to the three of them if they befriend this stranger? Could it change their lives forever? There is only one way to find out!