Plot: In which John Green teaches you about Sub-Saharan Africa! So, what exactly was going on there? It turns out, it was a lot of trade, converting to Islam, visits from Ibn Battuta, trade, beautiful women, trade, some impressive architecture, and several empires. John not only cover the the West African Malian Empire, which is the one Mansa Musa ruled, but he discusses the Ghana Empire, and even gets over to East Africa as well to discuss the trade-based city-states of Mogadishu, Mombasa, and Zanzibar