Terrible things happen to our hero in “Harry Potter and the Deathly Hallows” (Scholastic, 759 pages, $34.99), the last of seven novels in J.K. Rowling’s blockbuster series about a boy charged with saving the wizarding world. He uses Unforgivable Curses for the first time. He has a falling-out with his best friend and lashes out viciously at an old friend of his father’s. His presence endangers everyone around him. He dies, sort of.

No one said it would be easy. At the end of the series’ sixth book, “Harry Potter and the Half-Blood Prince,” the evil Lord Voldemort was back, the great wizard Albus Dumbledore was dead, and Harry had a killer homework assignment. Dumbledore theorized that Voldemort, seeking immortality, had split his soul seven times and stored the parts in magical objects called Horcruxes. This left Voldemort’s soul in raggedy condition, but meant that he could only be defeated if all of the parts of his soul were destroyed.

Two Horcruxes were taken care of in the first six books of the series. In “The Deathly Hallows,” Harry’s task is to neutralize the others and kill Voldemort. So he and his best friends, Ron Weasley and Hermione Granger, skip their last year at the Hogwarts School of Witchcraft and Wizardry to pursue the Horcruxes. They travel in secrecy, and the intermittent news they hear is hardly encouraging. Voldemort’s forces have taken over the Ministry of Magic. Severus Snape, who killed Dumbledore, is now headmaster of Hogwarts. Voldemort’s minions are trolling the land looking for what they call “Mudbloods” and “blood traitors” — wizards from nonmagical families and those who befriend them. Hermione is the former, Ron is the latter, and Harry, whom Voldemort wants brought to him alive, is the biggest prize of all.

All Harry, Hermione, and Ron have to go on is a few guesses about what the Horcruxes are and where they might be stored. Their progress is slowed by Harry’s doubts about Dumbledore’s reliability. He wonders whether it would be better to give up the Horcruxes in favor of the Deathly Hallows of the title, three magical objects that, together, would make the owner the master of death. The squabbling trio alternates camping in remote parts of the countryside with visits to key spots in the wizarding world.

It is to Ms. Rowling’s credit that she has managed to keep millions of readers in suspense about whether her hero will survive. But no one would seriously expect Harry to die halfway through the last book. So the scene in which a little old witch transforms into Voldemort’s snake Nagini and attacks Harry is not too scary. The story of how Dumbledore’s youthful arrogance led him into an unsavory alliance is fascinating background, but a needless distraction to readers anxious to know what becomes of everyone. Snape, one of the most complex and intriguing characters, has little face time in this last book.

Most of all, readers will miss being at Hogwarts. Throughout the series, the school has been the main site for adventures, jokes, domestic drama, and danger. When Harry finally arrives there, three-quarters of the way through the book, the action is engrossing. The Battle of Hogwarts is nothing short of thrilling. Everyone shows his or her true colors, and Harry confronts his destiny once and for all.

The series thus far prepared readers for a cataclysmic finale, and there are plenty of casualties in this battle. The self-sacrifice of Dobby the house-elf is unexpectedly harrowing, and this reviewer was wiping her eyes on a beach towel at the death of her favorite character. But the book nonetheless offers ample suspense. Fans have been preoccupied with certain key questions: Will Harry live? Is Snape really evil? On these, Ms. Rowling keeps readers guessing to the final pages. And Harry’s rapprochements with his cousin Dudley and the Death Eater Narcissa Malfoy are all the more touching for being surprising.

“Harry Potter and the Deathly Hallows” may be uneven in its first 500 pages, but fans of the boy wizard will be pleased with how it works out, and why. Early in the book, Harry gets grilled for “Disarming” an opponent — casting an elementary spell that makes a wizard lose his wand — rather than using more forceful magic. But that simple spell serves Harry well over and over again in “The Deathly Hallows.” Harry has never been a technically proficient wizard. He distinguishes himself through courage and love, and it is in these traits, Ms. Rowling suggests, that real magic lies.

Ms. Grieder is the Southwest correspondent for the Economist.