Like his fellow lunarnauts living on Moon Base Alpha, twelve-year-old Dashiell Gibson is famous the world over for being one of the first humans to live on the moon. And he's bored out of his mind. Then Moon Base Alpha's top scientist turns up dead. Dash senses there's foul play afoot, but no one believes him. But Dr. Holtz was on the verge of an important new discovery, Dash finds out, and it's a secret that could change everything for the Moonies: a secret someone just might kill to keep.