Hermione sighed and looked back down at her book. Snape had been gruffer with her over the past couple days, and she knew it was because his Dark Mark was hurting him. He never said anything to her about it, but she could tell from the way he rubbed it on occasion or gripped his arm suddenly with his other hand if the pain was particularly bad. She had often wondered why Voldemort had not ended the connection between them when Snape had revealed himself as a spy and traitor, but since spending a lot of time with Snape, she had discovered the reason. Voldemort wanted a way of reminding Snape he knew of his betrayal and intended to have his revenge.