In an alternate 1914 Europe, Austrian Prince Alek, on the run from forces who are attempting to take over the globe with machinery, forms an alliance with Deryn, who is learning to fly genetically-engineered beasts.

In a dark future America that has devolved into unending civil wars, orphans Mahlia and Mouse barely escape the war-torn lands of the Drowned Cities, but their fragile safety is soon threatened and Mahlia will have to risk everything if she is to save Mouse, as he once saved her.

"Lozen and her family, on the run from the tyrants who once held them hostage, embark on a journey along a perilous trail once followed by her ancestors, where they meet friends and foes alike"--Publisher.

On a planet on the brink of total destruction, teenager Remy is determined to find her missing friend, Alora, but the only way to track her down amidst the chaos is to team up with a traitor to stage a revolution.