On each landing, opposite the lift-shaft, the poster with the enormous face gazed from the wall. It was one of those pictures which are so contrived that the eyes follow you about when you move. BIG BROTHER IS WATCHING YOU, the caption beneath it ran. (...) But the face of Big Brother seemed to persist for several seconds on the screen, as though the impact that it had made on everyone’s eyeballs was too vivid to wear off immediately.