Bag-snatchers are at large in Ashfordly and the police know that Ian 'Duster' Murray and Robert 'Red' Broadbent are the perpetrators, but cannot prove it. When they attack Phil Bellamy's grandmother he takes it personally and gets determined to see them behind bars at any cost. Greengrass is also in great demand. Mr. Braithwaite has died and his daughters Joan and Norma are convinced that he hid his will in his stuffed prize ram and that Greengrass knows where it is. Jo's mother has become ill and she does her best to make Jo feel bad about it, because she will not break up her engagement to Nick and Fiona Weston cannot keep up appearances when her daughter is married to a common village bobby.

Alec Formby and his fiancée Sonia Harding are on route with a radioactive isotope to a laboratory in Leeds and make a stop at the Aidensfield Arms to get something to eat. When they have finished their car has been stolen. The Police recover the car again after it has been involved in an accident, but the lead bottle containing the isotope is gone. Greengrass' brother Cyril calls on him with a business proposition He has bought a racing dog and needs a place to keep it for a couple of days. The dog is very fast and Greengrass races the dog without his brother's knowledge.

Stuart and Trevor Chivers are at it again. Stuart has got detention with a classmate, Bernie. In revenge Bernie smashes the windscreen of the teacher's car, but the teacher Mr. Powell thinks Stuart did it. When PC Bradley questions him about it, he runs away. He is found the next day with severe stomach pains. PC Bellamy's grandmother complains about lorries rumbling through the village at night. The police cannot do anything about it, so she promises to take action herself. Oscar Blaketon has become WPO of Aidensfield and as such he is responsible for putting the village on alert in case of a war and for the village fallout shelter. Greengrass knows the perfect place for such a shelter, and he and Bernie Scripps are selling accommodations in it for a token annual fee for maintenance with great success.

An old man is attacked in what appears to be an open-and-shut case of burglary.