In 1914, on the eve of war, a fugitive prince and a girl in disguise meet aboard a bioengineered airship, the HMS Leviathan, and change the course of history.
Alek, a fugitive prince of the Austro-Hungarian Empire, and Deryn Sharp, a daring young girl disguised as a boy to serve in the British Air Service. When fate throws them together aboard the HMS Leviathan, a massive, living airship made from genetically engineered creatures, they embark on a world-changing adventure that will challenge everything they know about war, loyalty, and identity.