Harry Potter and the Half-Blood Prince (movie)
As the school year begins, Harry's friend Ron Weasley falls in love with Lavender Brown, making Hermione Granger upset. Harry finds a potions and spellbook written by a former Hogwarts student who called themselves the "Half-Blood Prince". A half-blood is a wizard who has one magical parent and one non-magical parent. Pure-bloods have two magical parents while muggle-borns have two non-magical parents. Voldemort wants rid of all wizards who are not pure-bloods.