Warning: Wikipedia contains spoilers
Jarvis Stringer is a student of the London Tube and its history and of underground trains worldwide. In order to finance his hobby and be able to travel to distant lands to inspect the underground systems in other parts of the world, he lets rooms in an old disused school building he has inherited which is close to the tube tracks in West Hampstead (see Jubilee Line). There, a group of misfits and weirdos, including a squatter, gather whose dreams of the good life have time and again been shattered as they are constantly victimized by society. There is 24 year-old Alice, an aspiring musician who leaves her husband and new-born baby only to end up busking in various stations in central London. There is Tom, who, after an accident, drops out of music school and is reduced to busking as well but who dreams of one day starting his own business. There is unemployed Tina, whose promiscuity landed her with two children whom she does not take care of in the way her mother thinks she ought to. There is Jed, who volunteers as a vigilante and who, disappointed by humans, lavishes all his love on the hawk he has acquired and which he keeps in the house. And there is Axel, an enigmatic man who regularly travels on the tube in the company of a man disguised as a bear and who is planning something illegal.
Cecilia and Daphne, two old ladies living in the neighbourhood, serve as a foil to this ill-assorted group. It is Cecilia in particular who does not understand how young people such as her daughter Tina can be utterly devoid of morals. She is shocked to learn that her 10 year-old grandson enjoys riding on the roof of cars as they go through deep-level tunnels.While travelling on the tube herself, her handbag containing her credit cards is stolen, and she suffers a stroke in one of the packed cars.
The novel is interspersed with extracts from Jarvis Stringer's (fictional) book on the London Underground.