Harry had reached for his staff when Edward had drawn the gun, but had hesitated a moment --
"Blood will work. Or, hell, I could probably track him by anything of yours, if he's as closely bound to you as you say he is. Hair or something. But blood would be better, if you don't mind."
He eyed Edward, a bit uneasy with what the hell just happened, and put a hand on William's shoulder. Losing a parent wasn't easy: Harry remembered when his own father had died. And at least Harry had closure -- he had known what had happened, and why he had to go live with Justin. Thinking that his father had foist him off...
... well, it was easy to see what that could do to a person.