In January 1940, a German double agent warned the FBI, “Watch out for the dots! Lots and lots of little dots.” During World War II, German Abwehr agents used microphotography to reduce classified military documents down to a dot, entrusting the period with sensitive intelligence such as tank specs and bomb sites, as well as meeting coordinates, a time and a place. Administered to the page by syringe, the dot traveled under the guise of punctuation and was then enlarged by its recipient—blown up in a world that would ultimately be reduced to rubble. The end of the line harbored secrets. —