Lots of great bits in this Atlas Obscura story about the Manhattan Project‘s librarian. J. Robert Oppenheimer selected Charlotte Serber, a University of Pennsylvania graduate, statistician, and freelance journalist to organize and lead the scientific library at Los Alamos not because of her library experience (she had none), but because “he wanted someone who would be willing to bend the rules of cataloguing.”

At one point Oppenheimer sends Serber and her husband to Santa Fe and personally spread false information about Los Alamos to dispel any true rumors:

The Serbers entered a local bar with the express intent of telling residents that the Los Alamos scientists were building “an electric rocket,” rather than a bomb. But no one seemed to care. At one point, Charlotte danced with a local man, all the while pestering him about Los Alamos. “What’s your guess about what cooks up there?” she asked. “Beats me,” he said. “Don’t care. May I have another dance later?”

In fact the secrets almost did get out. The Santa Fe Library sent out routine letters to library card holders, which reached scientists at Los Alamos:

A small crisis ensued. The security teams demanded to know how the Santa Fe Library had obtained the names of so many Los Alamos scientists. As a result, “a dark and cryptic gentleman appeared to find out how this flood of mail happened to be sent them and where All Those Names were obtained.”

Turned out, many scientists, impatient with the long wait for books, had gone into Santa Fe and checked them out themselves, under their real names—a major security violation.

When the Santa Fe librarians explained this, the man left. “If a strange character with a long cigar and his hat over his eyes tailed the staff members, they were not aware of it and feel that he could rarely have had a duller assignment,” the library later wrote.

Read the whole story here.