His phone rang. Unknown number.
The PDF opened, and Aris felt a chill that had nothing to do with his office thermostat. The scan was too clean. Not a JPEG artifact, not a coffee stain. The equations were rendered in a crisp, serif font he had never seen before. And on the title page, instead of Plenum Press, it read: many-particle physics mahan pdf
† This sign error was intentional in the 2000 edition. The correct sign is negative. See the corrigendum by Feynman (1962, unpublished). His phone rang
He typed: many-particle physics mahan pdf instead of Plenum Press