"She's mentally stalking Celesca, as you know," Hermione hissed bluntly. Harry swore violently in agreement. "But it goes far deeper than that. She was going to use her in some sort of ritual, trying to force her soul into the creation of a baby with Riddle, so they could control the powerful empty vessel of a body afterwards. I can only assume she created some kind of mental link to her as part of that. It's how she has been able to enter her dreams and torment her."