How can this chapter be seen to emphasize an awakening of a kind for Winston? (BOOK 2 CHAPTER 10)

This is the chapter when Julia and Winston are finally busted. They have in fact been watched all along. The voice comes from behind the picture of St. Clement’s Church: Mr. Charrington is the thought police. Winston knows it is finally over. He has slumbered in this dream with Julia and now it is time to wake up in Hell. Nobody goes unnoticed: Winston had known this all along.

why does Winston get caught now? why is this even taking place right before book three?

Please submit each of your questions separately. Thanks.