In George Orwell's 1984, what are major events that occur between the end of Part One and the end of the novel?

The last two parts of George Orwell's 1984 are marked primarily by Winston's growing doubt about the nature of society, specifically the motives and methods of the Party, Winston's increasing attachment to Julia, like Winston someone not satisfied with the current state of affairs, and their eventual capture and interrogation at the Ministry of Love.

In Part One, Winston expresses his uncertainties concerning the Party and the government of Big Brother as a whole.  The journal Winston purchases from a shop in the Prole area facilitates Winston's expression of his discontent.  Writing his thoughts in the journal allows Winston the opportunity to say what he wants to say about his perspective on society and the Party.  Winston's discontent and doubt only grows in Part Two. 

In Part Two, Winston begins to interact with Julia, someone who has a genuine hatred of the Party and what it represents.  Her feelings towards the Party, though often much stronger than Winston's, connect the two of them, and they begin to have an affair.  Through the course of the affair, they begin to talk about their discontent more openly, even suggesting they do something about it. 

Their affair culminates in Winston and Julia being captured and taken to the Ministry of Love at the end of Part Two.  Part Three, more than either Part One and Part Two, affords the reader a closer view of how the Party works, specifically the inner workings of the Ministry of Love.  Both Winston and Julia are interrogated by O'Brien, someone with whom Winston believes he had a rapport.  Through the course of the interrogation, both Winston and Julia give each other up.  When confronted with his worst fear, rats, Winston is very quick to have Julia put in his place rather than him.  O'Brien rather easily breaks down the relationship Winston and Julia believe they had, making it easier for O'Brien to work on Winston's mind.  Ultimately, O'Brien's and the Ministry of Love's approach is so complete that at the end of the novel, when Winston and Julia meet on the street, they treat each other as strangers, sharing none of the feelings that had passed between them before their stay at the Ministry.