Alek and Deryn encounter obstacles on the last leg of their round-the-world quest to end World War I, reclaim Alek's throne as prince of Austria, and finally fall in love.

Continues the story of Austrian Prince Alek who, in an alternate 1914 Europe, eludes the Germans by traveling in the Leviathan to Constantinople, where he faces a whole new kind of genetically-engineered warships.

"After the shocking conclusion to Swarm, the Zeroes are scattered, on the run, and desperate. They're up against challenges from within and from the world around them, and one thing is certain--an epic showdown is guaranteed"--

In a world that is rapidly descending into chaos, Frey and Rafi are twin sisters, but few people know of Frey's existence, because she has been raised to be her sister's body double and lethal bodyguard, while Rafi has been raised to further the family's political power--but when their father sends Frey in her sister's place as collateral in a tricky deal, Col, the son of a rival leader, gets close enough to begin to suspect something, and Frey must...

"Frey has spent her life in a family of deceivers, a stand-in for her sister, manipulated at her father's command. Free from them at last, she is finding her own voice -- and using it to question everything her family stood for. Tally was once the most famous rebel in the world. But for over a decade, she's kept to the shadows, allowing her myth to grow even as she receded. Now she sees that the revolution she led has not created a stable world. Freedom,...