"Narcissa and I were magically harmonious", he smirked, placing the book down on his desk. Hermione’s cheeks heated at his comment. She was no longer sure she wanted to know. "It means your magic is in tune with one another. It’s an ancient wizarding phenomenon - very rare these days. Your magic feeds off of one another. It’s stronger when you’re together. It often feels like electricity filling your veins, at least in my experience" It all made sense, yet it was still so strange to Hermione. This is what it was like being muggle-born, not knowing things like this.