When Bronwyn hears that her dad, Gareth, is putting on this year’s Pontypandy fireworks display, she remembers all the disasters he caused with fireworks when she was a child and sends Charlie along to keep an eye on his preparations. Gareth’s haphazard approach to the firework display is too much for Charlie to keep up with, he manages to space out the roman candles properly and check on the rockets but doesn’t see that Gareth has nailed in the Catherine wheel too tightly on to the door of Bessie’s shed. In the meantime, back at the fire station, Sam is giving Sarah, James, Norman and Mandy some lessons in the firework code. Later at the firework display, James spots the Catherine wheel and tries to warn Gareth that it’s nailed on too tightly. But it’s too late, it’s already lit. The Catherine wheel doesn’t spin and sets Bessie’s shed alight. Sam and the team race to the rescue and put out the fire leaving just enough time for everyone to have a go with a sparkler, safely, before heading home.