Prince Alek is on the run, with only a few loyal men and a machine to help him. Deryn Sharp just wants to be in the British Air Service, and she can! As long as no one knows she's a girl. When the two of them meet up, Clanker and Darwinist each has a secret to hide. Will they work together or be each other's demise? This trailer shares the book's backstory and shows exactly what a Clanker and Darwinist is, and why they are at war. Beautiful illustrations!