Yeah, that was pretty much it. "We both know that Scott wouldn't be able to do it if it needed to be done." Scott would at best, lock him up and then kill himself trying to find some way to save Stiles. And he was pretty sure Lydia wouldn't be able to do anything else, either. Allison? Maybe. He wasn't sure. But he also knew he couldn't ask that of her without her telling Scott and frankly, he didn't want to have that conversation with Scott. Or any of the others, for that matter. He didn't want to hear false assurances that things would be okay. He also didn't want them so afraid to be around him that everything would be uncomfortably awkward.
He knew it wasn't exactly a fair thing to ask of someone, even Derek. Maybe especially Derek, all things considered. But he didn't know anyone else well enough to know they would do what needed to be done if something needed to be done. And at least he felt confident that Derek would make it as fast and painless as possible.
Stiles nodded, rubbing the back of his neck. "Thanks, Derek." His voice was quiet.