He knew that the half-siblings were close, closer than anyone knew. Riddle had changed her, making her his first - his only youngling. He fed her from his own wrist, as she was loath to feed on humans, the true reason behind her absences from their feeding revels. He taunted her, and teased her, and whispered sweet nothings in her ear - Hermione, his precocious half-sister, a dhampir until he had made her whole.