You wake up and feel a tickle in your throat. Your head hurts. You're mildly annoyed as you get the kids ready for school and dress for work yourself. Meanwhile, an utterly epic war is being fought, just below your skin. Millions are fighting and dying for you to be able to complain as you drink your cup of tea and head out the door. So what, exactly, IS your immune system? Second only to the human brain in its complexity, it is one of the oldest and most critical facets of life on Earth. Without it, you would die within days. In Immune, Philipp Dettmer, the brains behind the most popular science channel on YouTube, takes readers on a journey through the fortress of the human body and its defences. There is a constant battle of staggering scale raging within us, full of stories of invasion, strategy, defeat, and noble self-sacrifice. In fact, in the time you've been reading this, your immune system has probably identified and eradicated a cancer cell that started to grow in your body. Each chapter delves deeply into an element of the immune system, including defences like antibodies and inflammation as well as threats like viruses, bacteria, allergies and cancer, as Dettmer reveals why boosting your immune system is actually nonsense, how parasites sneak their way past your body's defences, how viruses - including the coronavirus - work, and what goes on in your wounds when you cut yourself. Enlivened by engaging full-colour graphics and immersive descriptions, Immune turns one of the most intricate, interconnected, and confusing subjects - immunology - into a gripping adventure through an astonishing alien landscape. Challenging what you know and think about your own body and how it defends you against all sorts of maladies and how it might also eventually be your own downfall, Immune is a vital and remarkably fun crash course in what is arguably, and increasingly, the most important system in the body.