He did not remember any ending to his interrogation. There was a period of blackness and then the cell, or room, in which he now was had gradually materialized round him. He was almost flat on his back, and unable to move. His body was held down at every essential point. Even the back of his head was gripped in some manner. O'Brien was looking down at him gravely and rather sadly. […] Under his hand there was a dial with a lever on top and figures running round the face.[…]
Without any warning except a slight movement of O'Brien's hand, a wave of pain flooded his body. It was a frightening pain, because he could not see what was happening, and he had the feeling that some mortal injury was being done to him. He did not know whether the thing was really happening, or whether the effect was electrically produced; but his body was being wrenched out of shape, the joints were being slowly torn apart. Although the pain had brought the sweat out on his forehead, the worst of all was the fear that his backbone was about to snap. He set his teeth and breathed hard through his nose, trying to keep silent as long as possible.
"You are afraid," said O'Brien, watching his face, "that in another moment something is going to break. Your especial fear is that it will be your backbone. You have a vivid mental picture of the vertebrae snapping apart and the spinal fluid dripping out of them. That is what you are thinking, is it not, Winston?" (3.2.12-16)
"What have you done with Julia?" said Winston.
O'Brien smiled again. "She betrayed you, Winston. Immediately-unreservedly. I have seldom seen anyone come over to us so promptly. You would hardly recognize her if you saw her. All her rebelliousness, her deceit, her folly, her dirty-mindedness – everything has been burned out of her. It was a perfect conversion, a textbook case." "You tortured her?" (3.2.32-34)
He had stopped because he was frightened. A bowed, Grey colored, skeleton-like thing was coming towards him. Its actual appearance was frightening, and not merely the fact that he knew it to be himself. He moved closer to the glass. The creature's face seemed to be protruded, because of its bent carriage. A forlorn, jailbird's face with a knobby forehead running back into a bald scalp, a crooked nose, and battered-looking cheekbones above which his eyes were fierce and watchful. The cheeks were seamed, the mouth had a drawn-in look. Certainly it was his own face, but it seemed to him that it had changed more than he had changed inside […]. Here and there under the dirt there were the red scars of wounds, and near the ankle the varicose ulcer was an inflamed mass with flakes of skin peeling off it. But the truly frightening thing was the emaciation of his body. The barrel of the ribs was as narrow as that of a skeleton: the legs had shrunk so that the knees were thicker than the thighs […]. The curvature of the spine was astonishing. The thin shoulders were hunched forward so as to make a cavity of the chest, the scraggy neck seemed to be bending double under the weight of the skull. At a guess he would have said that it was the body of a man of sixty, suffering from some malignant disease. (3.3.66)