In the spring of 1943, a package arrived at a Washington DC address that appeared in no telephone directory. Inside, wrapped in brown paper and tied with string, was a piece of silk embroidery: a cluster of chrysanthemums in deep gold and pale cream, breathtakingly beautiful. Captain Henry Lowell of the Office of Strategic Services took it to his desk, picked up a magnifying glass, and began to read. Behind the barbed wire of the Manzanar War Relocation Authority Center, in the high desert of the Owens Valley, seven Japanese-American women had just committed an act no one had expected them capable of. They had turned the centuries-old silk embroidery tradition of nuido into one of the most secure and unusual intelligence networks of the Second World War. In the angles of the satin stitches, in the sequence of the colors, in the almost imperceptible variation of thread tension running through each piece like a coded pulse, they had encoded military intelligence about Japanese diplomatic activity, merchant shipping, and war economy conditions, gathered through the family and community networks that their government had imprisoned them for having. The government that had stripped them of their homes, their businesses, and their freedom had not thought to take the needle. That was its mistake. The Silk Thread Army is the story of Haruko Tanaka-Wells and her six companions across thirty-two months in which they proved, one embroidered chrysanthemum at a time, that the premise of their imprisonment was wrong. Drawing on declassified OSS records, the Japanese American National Museum textile collection, the Densho Digital Repository oral history archive, and twelve years of family research, Hana Fujimoto-Wells recovers a chapter of American history as moving as it is extraordinary. Beauty was the code. The code was the argument. The argument was true.