In the late 13th century, the Mongol Empire—the greatest land power in history—took to the sea. Twice, Khubilai Khan launched enormous fleets against Japan, and once against Java, with disastrous results. This episode dives into the logistics, technology, and weather that doomed these amphibious invasions. We explore the Yuan dynasty's shipbuilding programs, the role of Korean and Chinese crews, the kamikaze typhoons of 1274 and 1281, and the 1293 Java campaign that ended with Mongol forces withdrawing from a tropical island they could never truly control. Along the way, we meet the Japanese samurai who defended Hakata Bay, the Mongol general Shi Bi, and the Javanese king Kertanegara whose defiance sparked the invasion. Why did the Mongols, masters of the steppe, fail so spectacularly at sea? The answers lie in politics, logistics, and the unpredictable power of nature. This is a story of ambition, resilience, and the limits of empire.