For a while, he doesn't. Castiel just lies there, hands limp in Sam's grasp, almost not trusting all this to be real.

"Leviathan," he murmurs. His good eye cracks open, searches for Sam. He nods. He understands, just wants the scene to end though. When he hears another voice, he flinches. It takes a moment for him to realize it's Dean on the phone, not Jason coming back home to deal out rightful punishment.

For now, he holds Sam's gaze, tries to relax himself.