In the harrowing days of WWI, aristocratic young Lady Thomasina Thretheway, known as Mina, longs for a useful role in the war effort. Will her high-ranking father trust her experience with codes well enough to give her an authentic task helping the Allied effort? When she manages to take the place of an injured operative and close family friend on a daring mission behind enemy lines, the story morphs into a full-fledged war adventure. Amid spy intrigue, coded messages, fairly improbable escapes, a budding romance, and bold derring-do, our quick-thinking, thoroughly engaging protagonist triumphs and the plot never slows. Garretson reaches beyond adventure, too, providing a haunting nuance to the horrors of war through her heroine's eyes. As Mina and cohorts advance toward troop encampments at the front at one point, she notes the scenario looked like something out of a nightmare, so bleak and desolate that it was as if all hope had disappeared from the Earth. An action-packed, yet sobering journey into the war to end all wars.--Anne O'Malley Copyright 2019 Booklist