Each volume of the adventures of our favorite little sorcerer, the emphasis is more to it. Harry learns more and more about the world, about magic, about his parents ... and evil! Yes in this fourth volume, we begin to see what life in the magical community of Great Britain losque Lord Voldemort was at its peak. This book is longer than the other but it is so addictive that once started, I could not stop reading when I finished. And I even advise to read it several times to understand, in the light of the outcome, the details that are believed harmless throughout the narrative.