Cas stepped into the airlock with her classmates and Sally. The inner door closed behind them. She heard a distinct hissing as the air was pumped out, which faded to silence as the air pressure dropped too low to support the transfer of sound. She felt a vibration through the floor as the outer door shifted away from its seal and began to open. A puff of dust blew in through the widening crack, and she felt a thrill of anticipation.
Air: Generation Mars, Book One
Coming in October
(image: composite of images from Luis Peres)