"He didn't speak for fully three days together. Not a single word. He was unbelievably angry. And the guilt ... for what he convinced himself was his fault over your suffering ... well, it was a phenomenon. Neville had to take him to an ancient Druid ritual space, gather everyone he could to build defensive wards, then just let Harry explode within it. I was there. It's the only time I've ever felt genuinely afraid of Harry. He was like an uncontrollable force and our Charms barely held. He exhausted himself just before he smashed through. We all had to rest for days afterwards just to recover."