Martin Muffett is an engineering student at Leicester University in early 1989, aged 22. He rents a room at the home of George and Pauline Mole. Being highly practical, as befits his chosen career, he re-hangs all the internal doors and gets everything working smoothly. Martin soon begins an affair with his 45-year-old landlady, Pauline, and cares nothing about the age difference. Little Rosie Mole soon accepts Martin as part of her family, for a while preferring him to her brother, Adrian, who is living in Oxford at the time.