In Harry Potter and the Deathly Hallows by J.K. Rowling ends the greatest series in all my life. This is Harry's last year and he doesn't return to school because he is determined to fulfill Dumbledore's tasks. Harry learns that he has to put his faith in his friends and he can't keep doing certain things alone. Harry, Hermione and Ron get themselves in situations concerning all magical creatures. Deathly Hollows is complex yet based on something so simple. In the story you lose a lot of loved ones and there is no mercy in war. While Harry searches the Hollows he learns how to defeat Death.
I would recommend, honestly, to faithful Harry Potter fans. People who really stuck through all the books from the beginning, no bandwagon movie watchers. This book is great because it really shows expect the unexpected, that you have to learn to trust your friends and family. Harry Potter and the Deathly Hollows changes your perspective that makes you wishing this wasn't the last book.