Winston's horrors and fear are brought to light in these chapters: He is betrayed by Julia and O'Brien, he is tortured and ruined, and every hope he had for a future without the Party is destroyed. Winston learns that Goldstein's book was written partially by O'Brien and that Big Brother exists just as the Party exists, eternal and omnipotent.
These chapters function much like the chapters of "the book," which Winston read earlier in the story; both serve to answer unanswered questions about the Party and its ideology. However, these chapters are more revealing and shed light on many of the things Winston has wondered about throughout the novel. He always understood how the Party wielded its power, but he never understood why; O'Brien explains to him that the Party seeks power solely for the sake of power, ironically like the bird or the prole woman singing just to sing, as Julia had observed earlier.
O'Brien tries to make Winston understand and employ the concept of doublethink; doing so will be Winston's only salvation, but Winston finds mustering the mental strength to do so difficult. This unwillingness to use doublethink has been Winston's downfall from the beginning and ultimately proves to be his breaking point.
