In this chapter, we learn that each person enters the refining realm at different stages of his or her life. For example, one person may be a tree, while another may be just a normal person. In other words, each person's energy sea is different from the other's, and each person has different doors to open. For instance, one door may be bigger than another, and one door smaller than another. This is why it's so hard for a person with the same door to ignore the bell. The bell interrupts the conversation, and the two of them discuss whether or not they should continue fighting. They both know that if they lose, they'll lose their arms forever, and that's why they're going to kill each other. They also know that they've both lost an arm, so they can't argue with each other anymore. They're talking about the fact that a lot of people in the dream land lost their arms when they were discovered, and so they were kidnapped and killed to replace their lost limbs. This isn't true, and it doesn't make any sense to them. They don't need to prove that he killed the children, they just need to provide some evidence.