 Frank takes a course in motorbike riding for a courier job with dodgy Mr. Hunt, who only took him as too dumb to ask questions, but can t even find the route, and the examiner gets run over by a similarly dressed motor-biker. Even his wife Betty dreads the idea of him behind the wheel and deliveries depending on his performance. At home, Frank tries out a self-made metal detector, dreaming of finding Roman remains. At his first delivery,  deamon king  manages to block the break, starting his usual wild ride, everywhere unsafe. At the other side of the radio, Mr. Hunt has even more trouble with the police, which calls Frank back, just as much a public danger, somehow arriving, even trough the river. CID arrests him too for spreading porn. As if that weren t enough trouble, he decides to defend his incompetent self in court, trusting on character witnesses, who prove painfully honest. This proves him guilty of nearly everything loathsome, but incompetent to pull of the crime.