Marco was silent for a moment. "On my world, there's the guys - Yeerks," he said quietly. It was weird, in a way, actually bringing up Yeerks without something without them already knowing they were from his world. But what did he get from not saying anything? Nothing. At least this way, the guy would know to be on guard. "They're these alien slugs. They crawl into your ear, and take over your brain. Control everything you do. They make you a slave in your own body. My friends brother, he was one of them. And when his Yeerk," Marco spat out the word, like it was filth, "coerced him into agreeing to let the slug keep using him as a his own personal meat body, they just said 'oh, it's his decision' and ignored us when we tried to tell them just exactly just exactly was wrong with letting someone who'd been a slave for years stay infested. They didn't even get him a psych eval."