A female codebreaker puts her future and her heart on the line in a stirring novel about love, loyalty, betrayal, and Cold War spy games by the bestselling author of The Secret Stealers.

1947: Adventurous Radcliffe graduate Catherine "Cat" Killeen cancels her wedding and upends a future that no longer suits her. At the behest of her professor and hungry for a challenge, Cat arrives in Virginia to work on a confidential military project. A student in cryptoanalysis, Cat is already ahead of the game--to assist in rooting out Soviet spies who have infiltrated the US.

Joining the "government girls" of Arlington Hall, Cat gains the respect of her superiors and the friendship of her peers. Then, on a night out in DC, Cat runs into Jonathan Dardis, her arrogant and privileged Harvard rival and newly minted agent for the FBI. What Cat and Jonathan share is a competitive drive and an attraction that's becoming just as spirited. They're also united in the same critical goal for America. Together, they're diving deep into the shadows of espionage.

The stakes of the codebreaking operation grow ever higher, and Cat's relationship with Jonathan opens her heart. Amid dangerous intrigue and grave secrecy, Cat is ready for every risk--no matter how personal the stakes get.