I agree with others that this movie was real good but was lacking a lot of the details. If you did not read the book you would have missed the following details. Severus' last name was prince and he was a half blood hence the name of the movie. He was the potions expert who owned the book. Explaining what the horcruxes are and that Dumbledore had accidently put the ring on and his hand was dying. They hinted at it a few times but a few words would have made it very clear. It seems the screen writer or the director was at fault on a lot of these short comings. I AM AFRAID THAT THE LAST AND MOST IMPORTANT BOOK WILL BE TRANSLATED INTO SOMETHING LIKE THIS MOVIE. THIS WOULD BE A GREAT INJUSTICE TO ROWLINGS WORK IN MY OPINION.