I loved this one. I‘ve been fascinated with the WWII female code breakers at Bletchley Park since watching Bletchley Circle. This book loosely fictionalizes a few real women & creates an incredible historical novel. I loved the author‘s note at the end explaining what was fact & all the real people & events she included. The 3 main characters: debutante Osla, no nonsense Mab, & shy Beth, have depth & complicated motives. I loved their friendship.