J is either a compulsive mass-murderer reflecting on her life, or a delusional psychiatric in-patient reflecting on his; or, J is both. Possibly... An unnamed narrator describes her role as an operator' for an unnamed organization that appears to sanction random and violent assassinations. She looks back at her life, offering first-person accounts of her childhood, her schooling and the death of her father. She describes how she has come to work for the organization, the types of murders she has committed and the reasons for committing them. She shows no remorse. She offers no justification, other than to say that she is in the business of keeping her city clean. But all is not as it first appears. What is the organization; and why is a particular station on the London Underground so important to it? What is the nature of the training she has undergone; and why does it seem to be related to dark and violent forces at the heart of her childhood? It becomes clear that other voices are breaking through into her narrative: some in Russian, some as overheard conversations in English. The narrator may not be the woman she believes herself to be; these other voices may hold the key to her identity, as J'. The question is: exactly who or what is J?