In the sixth of her seven-book Harry Potter series, J.K. Rowling brings her long story toward its close, piecing together clues from all the earlier books. Young wizard Harry, who has survived so many plots by the vicious Lord Voldemort, has grown into a young man forced to live up to a legend he never wanted, indomitable in his essential kindness and cheerfulness (well, most of the time) but strengthened by grief and the unshakeable loyalty of his friends.

Rowling draws you into her world, so colorful and so terrifying, with a brilliantly steady hand. It opens with two introductory scenes — one entertainingly showing the Minister of Magic talking to the Prime Minister of muggle England, the other featuring Professor Snape, Harry's nemesis and unhappy ally. Picking up early in the summer, it takes a while to get to the meat of the story, even to the first days of the school year. But once it does the story moves as fast as ever.

As the wizard world copes with the increasingly brazen terrorism of Voldemort and his Death Eaters, Harry and his friends receive the all-important results from last year’s exams, which dictate what advanced courses they can take and what careers will be open to them. (Thankfully Harry avoided scoring “Troll” on any of his tests.) Facing harder challenges than ever in school, he finds unexpected help in an old textbook filled with useful notes from a student calling himself only “the Half-Blood Prince.”

Meanwhile Harry spies on the ever-suspicious Draco Malfoy, whose father was revealed as one of Voldemort’s loyal followers, and studies with his mentor Professor Dumbledore the nature of Voldemort’s heritage and power. And he must slowly come to grips with the prophecy that says it’s his destiny, 16-year-old Harry Potter, to either kill the greatest Dark Wizard in the world — or be killed by him.

Naturally Harry and his friends Ron and Hermione spend more and more time pursuing the opposite sex, flirting and kissing and pining away. It’s all quite innocent in comparison with real-world teens (this is meant to be a kids’ book, after all) but downright racy compared to Harry’s earlier tales. For his part, Harry slowly sees one of his best friends in a new light, realizes she means much, much more to him than he thought — and wonders if his friendship with Ron can stand the strain.

Rowling deftly leavens her mystery with humor, especially in the family of Harry’s friends, the Weasleys. Ron’s brothers, twins Fred and George, defiantly spread cheer in the face of terror in their new shop for magical tricks and pranks. (“Why are you worrying about You-Know-Who? You should be worrying about U-No-Poo — The Constipation Sensation That’s Sweeping the Nation!”) Ron’s younger sister Ginny, the lone girl in a house full of trick-playing boys, has grown ferocious when her brothers step on her toes. The locator “clock” at the Weasley home, which once showed each family member’s location — “work,” “traveling,” “school” — now shows the same thing for all: “mortal peril.”

For all the whimsy of the wizarding world, its darkness is deeper than ever. With Voldemort and his Death Eaters murdering enemies left and right, the wizard community is gripped by fear. Arthur Weasley insists that his wife demand a password before letting him the front door. Wary of dark magic, school caretaker Filch scans students leaving and returning to Hogwarts with a Secrecy Sensor. It’s a tribute to Rowling’s skill that the parallels to the real world are obvious but never gimmicky; the real terror we face in the news every day informs her story chillingly.

The last few chapters of Half-Blood Prince become increasingly grim, in places horrific. At the end we leave Harry poised to set off on the last quest to vanquish Lord Voldemort, thrilled with his courage and the strength of those still around him but heartbroken by betrayal and loss. Harry Potter and the Half-Blood Prince leaves you emotionally spent — and desperate for the next installment in the tale.

As if her staggering popularity left any doubt, J.K. Rowling is a masterful storyteller. When the seventh and final book comes I’ll hate the thought that Harry’s stories are at an end. But what an end it will be!