The Mole family's neighbour Mr. Lucas is left by his wife, Mrs. Lucas. He and Adrian's mother Pauline have been having an affair, and they both leave to go to Sheffield, leaving Adrian and George, his father, on their own. Adrian meets old age pensioner Bert Baxter as part of the 'Good Samaritan' project at his school. Bert's filthy house and habits disgust Adrian, but they become friends. School bully Barry Kent begins demanding 'money for menaces' from Adrian, until Adrian's grandmother puts a stop to it by confronting the bully. Adrian takes a trip to Sheffield to see his mother and her lover, Mr. Lucas.