Aziraphale saw the gun, and did not flinch, eyes trained on her face. "Simply to wish you hello," the angel told her, biting his tongue on his usual 'my dear'.

Patronizing War - even though he meant it sincerely and might perhaps only come off as patronizing - would be an excellent way to be shot, and Aziraphale didn't fancy going back Up Above and explaining to his superiors what happened to his old body.

But she was acting defensive, and that made him nervous. "You haven't got anything going on about here, have you?"