She would whisper these words to me mostly at night because that's when the monsters like to come out. At night when the walls would vibrate from machinery humming in the service tunnels and sub-basements below. I needed to hear those words when the wind would scream and howl from the unstable air currents and unpredictable weather patterns that came with an atmosphere being changed by a terraforming station. The turbines from dozens of filtration exchange towers ensured the sky was never still as it took in the cold, alien environment and infused hot oxygen-nitrogen gases into the air. Just like the rhyme my daddy would sing with me, "Bad air goes in, good air comes out."