In chapter 10 how are Winston and Julia captured?

In Part 2, Chapter 10, Winston and Julia are at their hideout ath Charrington's shop.  They have recently gone to O'Brien's apartment.  O'Brien invited them to come and get a new Newspeak dictionary.  While there, he pretended to be a member of the resistance.

In Chapter 10, Winston and Julia have been sleeping so they are still in bed.  They don't know there is a telescreen in the room (it's behind a picture) but all of a sudden it starts joining their conversation, making fun of them.  A soldier bursts through the window, some more of them through the door.  They arrest Winston and Julia.