Billy looks into Kaworu's dark eyes, sees that red. He searches for a sign that his trust in his friend wasn't misplaced. And deep within, with a soft nod, he finds it. His heart is telling him not to give up, and he's going to listen. He gives Kaworu a small encouraging smile. He doesn't drop his guard completely again, but it's lowered enough.

"Don't worry, I'm still listening."