“Where do we start?” Ron Weasley (Rupert Grint) asks Harry Potter (Daniel Radcliffe) near the beginning of “Harry Potter and the Deathly Hallows Part One,” the penultimate installment of the series. Unsure how he, Harry, and Hermione Granger (Emma Watson) will find and destroy Lord Voldemort’s four remaining horcruxes, Ron poses the question that will serve as an impetus for the film’s plot. One can certainly imagine director David Yates and screenwriter Steve Kloves asking each other the same question as they faced their own insurmountable task: adapting J.K. Rowling’s final novel in Harry Potter’s saga into a coherent movie.

Most notably, Yates and Kloves split “Deathly Hallows” in two. This decision was fairly unavoidable, given the length of the novel and the significance of most of its scenes. The presentation of the first half of the book leaves “Deathly Hallows Part One” feeling slightly unsatisfying, as nothing is actually resolved. However, Kloves—and in particular Yates—have done an admirable job of turning a lengthy, fast-paced book into a stimulating cinematic experience.

The script of “Part One” adheres closely to its source text. Much of the film, such as the scene in which Mad-Eye Moody is pronounced dead, is taken almost verbatim from the book. As pleased as many fans will be with this, the move is not necessarily a recipe for automatic success—the first two Potter movies did not stray far from Rowling’s books, yet their poor acting and minimal direction made them the worst among the films. “Deathly Hallows” is a particularly difficult book to adapt, since it is so different from its predecessors. There is no Hogwarts, no Quidditch, and little magical diversion to entertain the audience. Guest actors, who have often carried the Potter movies, are mostly absent, and those that do appear here (Bill Nighy as Rufus Scrimgeour and Rhys Ifans as Xenophilius Lovegood) contribute nothing remarkable with their characters. What we do have is Harry, Ron, and Hermione trekking across the British countryside in an increasingly dark and dismal hunt for the horcruxes that possess Lord Voldemort’s immortality.

Left to carry the brunt of the acting, Radcliffe, Grint, and Watson continue to demonstrate what has been evident from the last two Potter movies: they have truly grown into their roles. Radcliffe is particularly rewarding to watch, delivering his most mature performance yet as his character attempts to lead his friends on a seemingly impossible journey. His chemistry with Watson (which culminates in by far the most surprising scene in the whole series) is notable for its believability, actually eclipsing what Grint manages in his scenes with his character’s future wife.

As effective as the three actors are, it is Yates’s brilliant vision that carries the movie. Yates takes Harry, Ron, and Hermione to just about every corner of Great Britain, situating their tent in some of the most bizarre but beautiful spots imaginable. Throughout the journey, the cinematography is innovative and noteworthy. When the trio’s camp is approached by a group of hostile “snatchers,” the camera rotates around Hermione and one of the outsiders, successfully emphasizing the precariousness of the group’s position, as well as their isolation.

Yates likewise takes full advantage of the many avenues for cinematic exploration in Rowling’s book. The gothic animation of “The Tale of the Three Brothers” is one of the movie’s highlights, successfully adapting the children’s tale into a haunting but gripping addendum to the live action of the film. The two scenes with Polyjuice Potion—Harry’s escape from Privet Drive and the break-in at the Ministry of Magic—are extremely funny. Radcliffe superbly acts as seven copies of himself, conveying the other characters’ personalities perfectly, from Fleur Delacour’s neediness to Mundungus Fletcher’s skullduggery. At the Ministry, David O’Hara adds a delightfully comical slow walk and general uncertainty to Harry masquerading as the Death Eater-sympathizer Albert Runcorn. Yates controls both action-packed and sedate scenes with an assured hand, ensuring the movie proceeds at a steady but unrelenting pace.

For all the success of this adaptation, however, it remains the case that a perfect movie adaptation of the Harry Potter books is probably impossible. Just like all of the Harry Potter films, “Deathly Hallows Part One” will be incomprehensible to anyone who has not read the books. Kloves makes some effort to explain details that previous movies missed (such as how Bill Weasley was attacked, or what the Trace is). However, many points—like the significance of the mirror Harry keeps looking at or how the heroes suddenly learn to apparate—simply go unmentioned. Such significant omissions mean that the movie series will never be able to stand alone—it can only ever be an enjoyable accompaniment to the books.

It is hard to criticize Kloves for his cuts, however, since it is simply impossible to retain everything important from Rowling’s book. Despite the considerable loyalty he showed to the text, significant omissions are unavoidable. One notable storyline that is played down is Harry’s doubts about Dumbledore’s intentions. Dumbledore’s family scandal and adolescence is hinted at, but its significance for Harry’s quest remains unexplored. Hopefully “Deathly Hallows Part Two” will delve into Harry’s suspicion of Dumbledore’s motives and the angst that such worry causes him—the resolution of which proved one of the richest and most rewarding additions Rowling made to the final book.

In this as in other issues, it is hard to judge “Deathly Hallows Part One” before “Part Two” is released in July. But “Part One” seems to be a very satisfactory step towards a successful conclusion of the series. Yates’s steady hand guides the series onwards, with the continuing improvement of the movies now an undeniable fact. The Harry Potter movies will never be perfect, and they will never live up to the books. But for now, we can certainly make do with an impressive penultimate installment.

—Staff writer Chris R. Kingston can be reached at kingston@fas.harvard.edu.