O'Brien spends the next few months torturing Winston in order to change his way of thinking — to employ the concept of doublethink, or the ability to simultaneously hold two opposing ideas in one's mind and believe in them both. Winston believes that the human mind must be free, and to remain free, one must be allowed to believe in an objective truth, such as 2 + 2 = 4. O'Brien wants Winston to believe that 2 + 2 = 5, but Winston is resistant.
Finally, O'Brien takes Winston to Room 101, the most dreaded room of all in the Ministry of Love, the place where prisoners meet their greatest fear. Winston's greatest fear is rats. O'Brien places over Winston's head a mask made of wire mesh and threatens to open the door to release rats on Winston's face. When Winston screams, "Do it to Julia!" he relinquishes his last vestige of humanity.
Winston is a changed man. He sits in the Chestnut Tree Café, watching the telescreens and agonizing over the results of daily battles on the front lines. He has seen Julia again. She, too, is changed, seeming older and less attractive. She admits that she also betrayed him. In the end, there is no doubt, Winston loves Big Brother.
