London centers on Ferdinand, the protagonist of Céline's London who is a gravely injured WWI soldier with a severe wound to his ear and  suffers from both vertigo and the endless noise he can't stop hearing: I caught the war in my head. It's locked up inside my head. Ferdinand has earned a reprieve as well as a medal, and he has left France to join his prostitute friend Angèle in London. Despite his decoration, he nevertheless fears being sent back to the front and, in semi-hiding, takes up residence in an attic room where his pal Cantaloup runs an intense sex- trafficking operation. Colorful characters populate London: besides Cantaloup and Angèle, there is the generous poor Jewish doctor Yugenbitz, the corrupt cop Bijou, an eccentric English aristocrat, a slew of pimps, a rich variety of whores, and the revolutionary former bomb-maker Borokrom.
London is also a sweeping, grand-narrative-as-funhouse-mirror of Céline's own dual profession of medicine and writing: It's true I was sick and in a lot of pain and so I was justified. The consolation of having found Yugenbitz and the path, and the way that he'd given me hope to understand his beautiful work, that had sort of intoxicated me, I admit. I'm a little too enthusiastic about things of the mind. I'd have liked I think to cure all human diseases, so they'd never suffer again, the bastards. We're a strange lot, if we only admit it. Fine.