The Ministry of Magic is defeated for defeat in battles with Voldemort. Even Muggles suffer from the second war - every day disasters occur, the causes of which are not known to anyone. But in war, life continues. Harry, Ron and Hermione, like all sixteen-year-olds, study, go to parties and fall in love. However, the danger is getting closer. Despite Dumbledore's best efforts to protect the school, very strange things happen at Hogwarts. The pool of memory this time will reveal Harry the biggest secret of the Dark Lord, and in order to win, Harry is forced to sacrifice the most expensive.. Which side will the mysterious Half-Blood Prince take in this war?