For roughly two thousand years, the best maps in the world showed a vast southern continent that did not exist. This deep dive traces Terra Australis from Aristotle's argument that a heavy northern hemisphere required a southern counterweight, through Ptolemy's enclosed Indian Ocean, Cicero, medieval debates about upside-down Antipodeans beyond a torrid zone of fire, and Gerardus Mercator's insistence that the Earth's constitution could not hold together without it.

We then follow a spectacular game of cartographic telephone: Marco Polo's gold-rich Locach, a scribe's slip that moved it south of Java, spiky German script that turned Locach into Boach and then Beach, and Mercator engraving Beach the Gold-Bearing Province onto his 1541 globe. The episode covers Charles V creating a governorate for land no one had seen, Abel Tasman's 1642 order ...