The third episode covers the early centuries AD, the time of the Roman Empire. In this period, India, located at the "center of world, " became a great player in the first global economy. As the spice routes and the silk roads opened up, Indian civilization grew, enriched by contact and exchange. Beginning in Kerala, Michael Wood journeys on an old wooden sailing boat plying its trade from South India to the Gulf and relates how the spice trade with Rome opened India up to the world. He finds the lost site of the greatest Roman trading port, samples the earliest cuisine of India and travels by train to Madurai, the great ancient capital of south India. The film then shows how north India was opened up to the world at the same time, as merchants' caravans began to use the silk route between China and the West. Journeying to Merv in the deserts of Turkmenistan, Wood tells the story of the forgotten empire of the Kushans, who ruled India in the first centuries AD: one of the greatest and least known empires in history whose story can only now be told with the recent decipherment of their language. Coming down the Khyber to Peshawar in Pakistan, Wood finds the remains of what was then the greatest building in the world; traveling on to Mathura, he tells the amazing story of one of India's greatest rulers who laid the foundations of medieval India -- only to be overthrown in his own capital.