According to the released British security service files, Nazi agents relayed sensitive military information using the dots and dashes of Morse code incorporated in the drawings. They posted the letters to their handlers, hoping that counterespionage experts would be fooled by the seemingly innocent pictures.
British secret service officials became aware of the ruse and issued censors with a code-breaking guide to intercept them. “Heavy reinforcements for the enemy expected hourly,” is the message disguised as a decorative pattern in the stitching of gowns, hats and blouses in the line drawing above.
This discovery of hidden code, and the fact that it was concealed in an ad for women's clothes of all places, was the catalyst for my heroine Maggie Hope's foray into the world of espionage.
Thank you Evay, for sending that clipping my way!