It is the cusp of World War I, and all the European powers are arming up. The Austro-Hungarians and Germans have their Clankers, steam-driven iron machines loaded with guns and ammunition. The British Darwinists employ fabricated animals as their weaponry. Their <I>Leviathan</i> is a whale airship, and the most masterful beast in the British fleet. <P> Aleksandar Ferdinand, prince of the Austro-Hungarian Empire, is on the run. His own people have turned on him. His title is worthless. All he has is a battle-torn Stormwalker and a loyal crew of men. <P> Deryn Sharp is a commoner, a girl disguised as a boy in the British Air Service. She's a brilliant airman. But her secret is in constant danger of being discovered. <P> With the Great War brewing, Alek's and Deryn's paths cross in the most unexpected way...taking them both aboard the <I>Leviathan</i> on a fantastical, around-the-world adventure. One that will change both their lives forever.