When the monster realizes that he has been shot, he realizes that the shot must have come from outside, because the target was inside. He realizes that it is impossible to shoot through a window, since the target is so close to the ground. He also realizes that if the target were outside, he would not be able to see him, because he would be measuring the temperature of the ground around him. He then realizes that there is only one way to determine whether a person is a devil: by looking at his or her body. The only way to do this is to look at their faces, hands, and body temperature. The sight of a person's face and hands, he says, is the same as looking at a body's surface temperature. If you look at someone's body and compare it to the surface temperature of another's, you can tell if they are a devil or not. This is why he is killing devils, he explains, because no one will come after him if he is wounded. The monster then notices that his left arm is not moving, and that he is bleeding from the wound. He thinks that the wound must have been caused by the monster's reaction to the sound of his shot. He wonders if the wound was caused by his own gun, and wonders if he could have killed the monster if he had not been a devil. He decides to take 200 cc of human blood to fix his lungs.