"Do you want to know how I know about the fragment of Voldemort’s soul attached to mine?" Harry growled under his breath, and Snape’s eyes snapped to his, suddenly transfixed, "Do you want to know how I know about Voldemort’s Horcruxes?" Snape’s eyes were suddenly alarmed, and Harry realised that perhaps Snape hadn’t known about them at all, "Do you want to know how we’ve suddenly become exceptional students?" Snape’s eyes darted to Draco by the door and then back to Harry, "Do you want to know about Nagini? About how she killed you?" slowly, very slowly, Snape nodded, "Then you will send her  away!"