Book 6 | Ch:24 - Sectumsempra

SPOILERS:

Ron and Ginny are both single again, Katie Bell returns to Hogwarts but can’t remember what happened to her, and Harry sees Malfoy with Moaning Myrtle on the Marauder’s Map and runs to eavesdrop – but when Malfoy tries to hex Harry, Harry uses the Sectumsempra on him without knowing what it does and slashes him apart. Snape heals Malfoy but gives Harry detention during the Quidditch match, which Gryffindor wins anyway. Then, when Harry arrives at the party, he finally kisses Ginny.