Everyone's favourite Wee Granny is back with her magic bag, and Emily and Harry are desperate to see what she's got inside it today. It's the day of the school ceilidh, and they have to pick up last-minute supplies before the celebrations and dancing can begin. But things don't go smoothly - they miss their bus and then a flood closes the road. Does Wee Granny have something in her magic bag to save the day?