On the morning of April 29, 1986, a fire alarm sounded in the Los Angeles Public Library. As the moments passed, the patrons and staff who had been cleared out of the building realized this was not the usual fire alarm. As one fireman recounted, “Once that first stack got going, it was ‘Goodbye, Charlie.’” The fire was disastrous: it reached 2000 degrees and burned for more than seven hours. By the time it was extinguished, it had consumed four hundred thousand books and damaged seven hundred thousand more. Investigators descended on the scene, but more than thirty years later, the mystery remains: Did someone purposefully set fire to the library—and if so, who?