The Perils of a Covert Existence

We were a close knit group in those days, spending our working hours several floors underground. We knew close to a hundred languages between us, which allowed us to translate any document that came our way during the conflict. That is, until our commander brought us an intercepted missive and told us it was top priority, very important to the war effort. We took the document and leafed through it eagerly, only too ready to help our comrades in arms. Every page was completely blank. We were dumbfounded and frightened. We looked up, opened our mouths, but could not speak.