"I've thought it was likely, ever since Harry mentioned this mysterious link I had to Riddle through my Marriage Bond to Ron," Hermione confirmed calmly. "It made sense that I might have been involved somehow, but I had no clue how. But now, after Harry said Ron had Riddle curse me in person, I assume that's when he did it. He would have had ample opportunity to redirect my power to his Horcrux once Ron had given me over to Riddle, which I bet he did gladly."