In the world of covert ops, "Leaving No Trace" is the ultimate goal—but the environment is a persistent snitch. This episode explores the tradecraft of <b>Palynology (the study of pollen)</b> as a tool for tracking movement across international borders. We discuss how a specific microscopic spore on a shoe can reveal exactly where an operative has been, even if they’ve burned their passport. From the "Yellow Rain" mysteries of the Cold War to modern-day geolocation via plant DNA, we reveal why the "Greenery" is the ultimate counter-surveillance tool.