COVID-19 is far from the first pandemic to wreak havoc in the world. A long line of infectious diseases have devastated and in some cases destroyed entire societies. Almost all of them started in animals and made the jump to humans. We are terrified of pandemics. And with good reason. Infectious diseases have cost the lives of countless people over the centuries, devastating families, towns, and even societies. The Black Death spread across Europe and Asia in the 14th century leaving millions dead in its wake. Between the 15th and 18th centuries, European colonists brought smallpox to the Americas, the Pacific region and to Australia. In Europe, the 17th century saw a series of major epidemics. And at the end of the First World War, more people died of the Spanish flu than on the battlefield. This documentary examines the causes of these epidemics – whether it be lack of hygiene, interaction with animals, overcrowding, or the growth of cities – and how people travelling helped to spread disease and promote pandemics. It also sheds a light on the impact these infectious diseases have had on politics and societal change. Today, the world is facing COVID-19. Measures such as quarantine and lockdowns are being rolled out in an effort to control the spread of the virus; and, just as our ancestors did before us, some are questioning how effective they are. Over the centuries, scientists managed to develop treatments and medicines to help control or even eradicate infectious diseases. Virologists are facing that task again with the coronavirus, as the world frantically searches for ways to overcome a pandemic which threatens our modern way of life.