Philip K. Dick, A Scanner Darkly

One of the classic Dick novels, this is a story about a police officer investigating himself in order to unravel a drug cartel. Videotaping himself for later screening, the novel centres on sliding identities and the stress of acting as more than one person. The novel is as paranoid and excellent as only Dick can be at his best. Clearly inspired by his experiences in the drug community, it also serves as an interesting view into a part of society which many have little knowledge of. This is clearly on of the least sf novels he has written, though it can hardly be termed realist.