When I think of a really deadly disease, I think of rabies, because it's not only virtually 100% fatal, it is a horrible way to die. But "deadly" in this video doesn't mean the rate of death, but the number of people who die. Rabies is horrible, but it's not all that easy to catch. You might guess what the "white death" is, but since the video strings you along, I won't mention the exact disease. In this video, Kurzgesagt provides the art and John Green provides the commentary as we learn how the white death infects a human body and makes its way past our immune system. Of course, our immune systems always have a plan B, but that in itself can make us sick or even kill us. This slow, sneaky disease killed 1.3 million people last year. And that's a problem, because it's so slow and sneaky that we tend to ignore it despite the number of deaths. But there is hope on the horizon.