Cayden frowns. "What do you mean that isn't my brother?"
The boy—Lou—gulps. "It isn't him."
Cayden exchanges a glance with Sasha. Technically he was supposed to have this conversation with him in private, but she didn't excuse herself and he couldn't ask her to leave her own meeting room, could he? He's a guest here, he doesn't make the rules. When he heard that the boy came from FireMoon, his heart almost stopped beating altogether. He thought that perhaps he came with news from Mia.
Lou is telling him something that he never thought he'd hear from the mouth of a stranger.
But Lou isn't necessarily a stranger. He remembers Mia mentioning him vaguely. He's a boy that Cyran found in the city and he's kept him by his side ever since. Mia would take care of him back at the Nameless Pack. He was with Cyran for a long time, which means that he knows what he's talking about.