Doctor Aristotle ‘Ari’ Campbell is a scientist from the Core world of Britannia. As such, he's more used to the ivory towers of academia than the rough and tumble worlds on the Verge, where a barrier supposedly keeps out the ruffians of restricted space. He's only there because he's desperate to find his kidnapped twin brother Theo. To help him navigate the Verge and the restricted space beyond, Ari enlists the aid of Orin, a down on his luck pilot in desperate need of work and a ship.
Captain Draco commands an airship in Her Majesty Queen Victoria’s flying service. At a ball thrown by the Aztec emperor to celebrate Draco’s victory over pirates that had plagued trade between the two nations, Draco learns of a new assignment: he is to captain the first ship to travel in space, a joint venture between the British and Aztec empires. To “assist” Draco on his mission, the Aztec emperor binds Draco the Yolotli, a beautiful young man Draco assumes is a palace pleasure slave.