 Oscar Blaketon gets into trouble when two young criminals steal his car and run away from an accident they have caused, because he will not account for his whereabouts at the time of the accident and did not report the car stolen. Meanwhile the two criminals, Joey Sharp and Frank Collins, supplies drugs to the schoolgirl Lizzie Tyler and her friend Babs. Greengrass overhears how PC Bradley talks to a friend about buying classic motorcycles and spots an opportunity to earn a quit or two. He even knows where hen can get his hands on some if he can get Bernie Scripps to assemble them.