In an alternate London in 1923, one girl accidentally breaks the tenuous truce between dragons and humans in this sweeping debut and epic retelling of Bletchley Park steeped in language, class, and forbidden romance. Perfect for teen fans of Fourth Wing and Babel.

* New York Times Bestseller * #1 International Bestseller * As Seen in Cosmo * Audible Most Anticipated Audiobooks of 2025 *

Dragons soar through the skies and protests erupt on the streets, but Vivien Featherswallow isn't worried. She's going to follow the rules, get a summer internship studying dragon languages, be smart, be sweet, and make sure her little sister never, ever has to risk growing up Third Class. She just has to free one dragon.

By midnight, Viv has started a civil war.

With her parents and cousin arrested and her sister missing, Viv is brought to Bletchley Park as a codebreaker--if she succeeds, she and her family can all go home again. If she doesn't, they'll all die.

As Viv begins to discover the secrets of a hidden dragon language, she realizes that the fragile peace treaty that holds human and dragon societies together is corrupt, and the dangerous work Viv is doing could be the thread that unravels it.