The great clockwork solar system, The Orrery, is failing and young Wren has fled her homeworld to seek Sanctuary with the Engineman. In a quest to find the scattered knowledge required to restart the system he sends Wren and his young assistant, Conductor 17, along the long-abandoned rails connecting the planets to a world untouched for years. As civil war forments, Wren and Conductor 17 must use their wits if they are to gain the hidden knowledge they need to save the solar system!