For centuries mankind has waged war against the infections that, left untreated, would have the power to wipe out communities, or even entire populations. Yet for all our advanced scientific knowledge, only one human disease – smallpox – has ever been eradicated globally. In recent years, outbreaks of Ebola and Zika have provided vivid examples of how difficult it is to contain an infection once it strikes, and the panic that a rapidly spreading epidemic can ignite. But while we chase the diseases we are already aware of, new ones are constantly emerging, like the coronavirus that spread across the world in 2020. At the same time, antimicrobial resistance is harnessing infections that we once knew how to control, enabling them to thrive once more. Meera Senthilingam presents a timely look at humanity's ongoing battle against infection, examining the successes and failures of the past, along with how we are confronting the challenges of today, and our chances of eradicating disease in the future.