As the Earth spun, the Mediterranean Sea, that cradle of ancient tales, became a beast unchained. The Strait of Gibraltar, gateway to the Atlantic, slammed shut as the crust buckled, trapping the sea in a prison of land. The waters, driven by the planet’s sudden tilt, surged forth in a monstrous wave, 50 to 100 meters high, racing at 120 meters per second—faster than the swiftest eagle. Half the sea, 1.85 million cubic kilometers, broke free, pouring over the Sahara with a force that tore away the sands and stones of ages past.