Set in a war-torn reimagining of 1914, Leviathan follows 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 brings them together aboard the HMS Leviathan, a massive, living airship constructed from genetically engineered creatures, they embark on a world-changing adventure that will challenge everything they know about war, loyalty, and identity.