When Harry, Ron and Hermione in their sixth year at Hogwarts beginning, Harry is in possession of a mysterious potion tracking scrap book together, which was once owned by the unknown Half-Blood Prince. What should Harry do with the sometimes very obscure spells the book mentions? And meanwhile, he faces a difficult social life and let him Dumbledore gradually see information about the dark past of Voldemort. These lessons from Dumbledore will lead to the greatest mystery of the dark ruler and will help Harry to survive.