Tsuruzaki asks if it's too dangerous to let momoko go all alone. He says that if they want to kill momoko, they could just throw her out the train, and they have enough time to do so. But, instead, they kept momoko on the train with them. They don't want to lure them in, but they do want to buy more time. They want to know what happened at the train crash, so they're going to have to find out what happened. They're not going to run away, they say, because they were busy saving people. They were going to attack them while they were saving people, but since they were looking at them from the darkness, they have to pull them out of the light. They need more information, since they've seen them looking at each other from the dark. So, they need to pull out all the information they can from the light so they can figure out what's going on. They have to figure out how to get the information out so that they can pull out the passengers from the train. They can't do that because they'll have to look at them all in the dark, and then they can get more information about what happened in the crash. They also need to get more info about how they got the information, so that when they pull all the passengers out, they won't be able to see what happened to them. So they need more info, and that's what they do: they look at all of the passengers in the darkness and they see that they were all saved by the two of them.