Austrian Prince Alek, in an alternate 1914 Europe, eludes the Germans by traveling in the "Leviathan" to Constantinople, where he faces a whole new set of challenges. Book #2 Scott Westerfeld presents the sequel to his hit steampunk novel, Leviathan. In the midst of conflict with the Clankers, the Darwinists' war efforts rely on the behemoth, the largest, most feared creature in the British navy. Deryn, posing as a boy so that she may serve in the Air Service, finds herself aboard the Leviathan along with Alek, the heir to the empire, who is also in disguise. However, when the Leviathan's mission goes awry, Alek and Deryn must team up and outrun the relentless enemy.