It's a rigid life on Airship 11, although most of the crew members don't mind. But when young unit 009 receives a punishment only whispered of behind closed doors, she sets in motion events which will thrust her and the only people who help her-003, a spunky mechanic who lets nothing get them down and 004, their ambitious best friend who lets nothing get in her way-into an unknown world on the ground, where skeletal robots maintain order and vampires lurk in the shadows.