Your worst enemy, he reflected, was your own nervous system. At any moment the tension inside you was liable to translate itself into some visible symptom. He thought of a man whom he had passed in the street a few weeks back; a quite ordinarylooking man, a Party member, aged thirty-five to forty, tallish and thin, carrying a brief-case. They were a few metres apart when the left side of the man’s face was suddenly contorted by a sort of spasm. It happened again just as they were passing one another: it was only a twitch, a quiver, rapid as the clicking of a camera shutter, but obviously habitual. He remembered thinking at the time: That poor devil is done for. And what was frightening was that the action was quite possibly unconscious. The most deadly danger of all was talking in your sleep. There was no way of guarding against that, so far as he could see.