Where and how does Bernard make sure that the DHC won't send him to Iceland?
In this chapter, the Director calls Bernard Marx to him. He says that Bernard has been convicted of having improper beliefs and doing improper things. Bernard is accused of many things, including an unorthodox sex life.
What Bernard does here is the perfect response to this particular accusation. He brings Linda into the room and has her identify the Director. She tells everyone that he is "Tomakin" the man who is the father of her child. This completely humiliates the Director.
This happens in the Fertilizing Room at the Centre.