"Winter light. Got it. And you're Kaja?" He lapses into his original language. "I'm a bit terrible with names if I'm not actively reminding myself of them, apologies. So, medicine is not my specialty, but most diseases are caused by tiny creatures called bacteria or viruses. Or sometimes protists or fungi or parasites that are technically animals."

"At any rate, most of them are as small compared to a gnat as a gnat is to a griffon, maybe smaller. These things like to live inside humans because we're nice and warm and moist. The human body fights the ones that would do us harm if allowed to multiply. Sometimes, it stops winning, and that's when people get sick. Antibiotics and antivirals help the body fight the things. All of this is a vast oversimplification, of course."