Luna is ten years old. She's lived her entire life inside the walls of the spacecraft Scorpion, waking just seven months ago into a world of ducts, crawl spaces, and surveillance. She watches the crew from behind the panels-unseen, unheard, and far more perceptive than anyone suspects. When Ellie emerges from cryostasis, disoriented and alone, she's quickly befriended by AMEE, the ship's enigmatic AI. But something is wrong. Dr. Morrison is planning something catastrophic, and the ship's systems are beginning to fracture. As Luna pieces together the truth from the shadows, Ellie and AMEE race to stop Morrison before Scorpion is lost. But the key to saving the ship may lie not in the command deck-but in the quiet girl who's been watching all along.