Whatever he was planning next would remain a mystery to Hermione thanks to the ringing of the doorbell. Annoyed that he was being interrupted, Rodolphus" ire shifted from her to whatever poor soul awaited him outside his front door. He released his grip on her neck and exited the dining room like nothing strange or unusual just happened. She struggled to catch her breath and get her fear under control before he returned. Rodolphus was the sort of predator to smell weakness. Maybe it was part of his enhanced senses thanks to his animagus form.