Wing Commander Andy Carstairs likes to fly around in his beautifully restored Hawker Hurricane fighter from World War II. One night the airfield watchman is knocked down and two explosive wedges are stolen. A gang of robbers have been using that kind of explosives to break into security vans, but Sergeant Merton thinks it is a local job when another security van is robbed using one of the stolen wedges. David enters a yellow fuchsia on behalf of his Aunt Peggy's friend Mrs. Crompton in the Aidensfield Flower Show. She has had a fall out with the chairman of the flower society Hector Plumpton and reckons she will not have a fair chance. There is another reason also. According to Plumpton yellow fuchsias are impossible to develop. So the plant makes quite a stir at the show. So much in fact that it gets stolen.