The words give Essek some kind of hope, even if it's fragile and layered in the certain despair of how he's lost everything. He wants Ryo to be right so badly, he wants it to be true that Caleb is okay and he will be found. Never has he needed something to be as true in this moment as this. He made a promise to himself, that he would see him safely to the end of everything, he just...

With a trembling breath, he nods. "I-... hope you're right.."

His mind starts to go blank, like it's turning off, like everything is finally too much and it needs to just... disengage with everything. It makes him feel dead inside, even as his heart still pounds and his body still shakes, even as his breathing remains uneven. For now, he rests his head against his folded arms, trying to rest like Ryo said. They would need to move for safety reasons soon, then perhaps once at a safehouse he can see about finding his missing friends later.