The Boy Who Lived returns for his penultimate escapade in the most mature installment of the popular Harry Potter series. Harry has had to grow up fast, pushed early on into adult responsibilities. But J.K. Rowling’s subject matter may have matured even faster. Where “Harry Potter and the Sorcerer’s Stone” is a heartwarming tale of childhood adventure that appeals to the imagination, “Harry Potter and the Half-Blood Prince” is an unflinching look at war, death and love. For those of you who haven’t read the book, there are some minor spoilers here. Beware.

Zombies, cannibals, inbreeding, mutilation and murder : this is PG-13 material. That said, “dark” is an overused term when describing the latter books. Though the subject matter has changed, the message has always been one of hope despite frightening times – times when much is lost. Coping with loss has become a central theme in the series, and nowhere is that clearer than in “Half-Blood Prince.” With Voldemort and his followers taking power, each day is a gift, and the students are old enough to realize it.

Ron starts many a day by asking Hermione if anyone they know is in the obituaries. Security at school has been stepped up. This is where the story has been headed since the conclusion of “Prisoner of Azkaban,” but it’s hard not to draw correlations between what is happening in Harry’s world and what has happened in America since 9-11. More likely, Rowling is writing an allegory for World War II. Nonetheless, the message is just as relevant today as ever.

With everyone afraid for their lives – and turning 16 – romance has stepped up a notch on the students’ to-do list at Hogwarts. Those looking to see some familiar characters hook up will not be disappointed. Most of these couples have been brewing for several books, but some may be surprising.

This is a novel for answers. The explanations for puzzles that have been developing for thousands of pages of previous books do not disappoint. But the mystery isn’t gone. Several major questions still remain. Don’t be dissuaded from reading the book if you hear some of the surprises first. The twist at the end is not the reason these books capture the attention of so many readers.

Along with Harry and his adventures, Rowling’s writing style has matured by leaps and bounds without losing that special sense of humor that makes her earlier books so much fun to read. For the first time in the series, it feels like Rowling is completely comfortable with the characters and their story. The pacing problems that plagued “Order of the Phoenix” are nowhere to be found in “Half-Blood Prince.” Even the fast-paced action of “Goblet of Fire” seems slow in comparison. From the first chapter, Rowling pulls the reader in and doesn’t let go. With the state of things at the end of this book, it will be hard to wait another two years for the final installment.