I was introduced to Harry Potter when I was 16, right after the fourth book,Harry Potter and the Goblet of Fire, was released. Having learned of the series from an article, I devoured each volume with a sense of growing wonder. They weren’t just good. They were extraordinary. From then on, I have waited for every new installment as eagerly as millions of other fans.

At last the next one is here, the penultimate book of this septology. I’ll be honest,Harry Potter and the Half-Blood Prince isn’t my favorite J.K. Rowling book — that distinction goes toThe Goblet of Fire — but it ranks right up there.

One of the great pleasures of these novels has been watching Rowling’s storytelling skills develop. And she certainly spreads her wings inHarry Potter and the Half-Blood Prince.

Lord Voldemort now terrorizes the wizarding world with random murders and destruction. Whenever Hermione opens a newspaper, Ron asks, ”Anyone we know dead?” — a far cry from the bright and whimsical world we were first introduced to inThe Sorcerer’s Stone. The parallels with current events are inescapable: Students are searched for dangerous devices before entering Hogwarts, a renegade leader evades all attempts to capture him, and the Ministry of Magic throws innocent people in prison just so it appears that the government is doing something to resolve the crisis.

The children have changed as well. They swear when they’re upset — not that Rowling actually gives us the dirty words — make rude hand gestures, and are often caught snogging in corridors. To put it another way, they act like real teenagers.

Harry himself isn’t as angry or as angst-ridden as inThe Order of the Phoenix. In the past five books, he has survived numerous attacks; watched Voldemort kill Cedric Diggory, a fellow classmate; and lost his godfather, Sirius Black. In this volume, Harry follows Dumbledore’s orders despite their almost unimaginable consequences, and, again, loses someone close to him. No one can endure such hardships without being altered, and Harry is no exception. He’s tougher now, more self-possessed, and unafraid to challenge the authority figures around him. I admit, it’s a bit of a shock to realize that Harry Potter is quite nearly an adult.

The new tone is disquieting because it’s so different from what came before. Yet if Harry and his world didn’t continue to evolve, they would soon become nostalgic curiosities. It’s heartening, both as an author and a reader, to see that J.K. Rowling is brave enough to experiment with her beloved series, and that she has remained true to the emotional and physical development of her characters.

Rowling has given me more hours of reading pleasure than most other authors. Her epic stands as one of the great achievements in fantasy literature. And though I finishedThe Half-Blood Prince only a few hours ago, I have to ask her the question that every author who’s just published a novel dreads hearing: So, when’s the next book coming out?

(Paolini is the author of the best-sellerEragon. The second book in his planned trilogy,Eldest, is due in stores next month.)