This book continues the hard-driving, action-packed adventures of Alek, heir to the throne of the Austrian empire and current British prisoner of war, and Deryn Sharp, a midshipman assigned to the Leviathan. Their loyalties to their respective governments and philosophies are tested as their friendship grows; Alek is an Austrian Clanker and Deryn an English Darwinist. After the Leviathan is damaged by a German attack, Alek and his personal guard escape the airship and join a revolutionary group dedicated to the overthrow of the sultan of Istanbul. Meanwhile Deryn has been sent to sabotage a key military blockade in the Istanbul harbor. But true havoc doesn't ensue until the teens are reunited. This dynamite novel incorporates factual events of the early months of World War I: the assassination of Archduke Ferdinand, Churchill's confiscation of an Ottoman Empire warship, and the instability and revolution within the Empire. However, the elements of steampunk, biological and mechanical technology, sheer over-the-top adventure, and great storytelling make this a must-have addition to any speculative fiction collection. Thompson's sumptuous full-page illustrations capture the goings-on and contribute to the cinematic feel of the book.