When asked by his father how he liked Harry Potter and the Prisoner of Azkaban, a young boy at a preview screening replied, “Eh.” Think that’s rough? His younger brother asked to play Tic Tac Toe halfway through.

These kids speak the truth. Though there is much to admire about new director Alfonso Cuarón’s take, nothing can mask the fact that this installment is a bore. The same could be said about the book, the transitional quality of which strained even with J.K. Rowling’s colorful prose. Here streamlined only to the most important payoffs, Cuarón’s Azkaban just can’t find consistency.

A finer filmmaker than the franchise’s previous director (Chris Columbus), Cuarón’s go-round is beautiful to the eye, with many effects integrated as seamlessly into the story as Eternal Sunshine of the Spotless Mind. Most notably, Cuarón’s changing of seasons makes fun use of the Whomping Willow tree. And there are fine moments as the characters discuss hopes, fears and foibles, which the actors themselves convey nicely.

But the harmony of fantasy and emotion is all too brief, as the movie warbles into the range of a stiff Woody Allen drama. And that’s not just because jazz music wrangles its way into a bunch of scenes. The musical fast pace tries — and fails — to breathe life into scenes such as a ghostly bus ride with a shrunken Rastafarian head and confrontations with the shape-shifting Boggart creature. The only organic thrills come in the film’s final act, where the action and circular storytelling take hold.

Everything else in Azkaban is moody, and we’re not talking Mad Eye. The bleak, cloudy grays are perfect for scenes with the Dementors, ghastly ghouls who suck souls from the sad. But the film feels so chilly in every other spot, as if we needed visual growing pains to accompany the deep teen angst of Harry (Daniel Radcliffe), Hermione (Emma Watson) and Ron (Rupert Grint, who is still a great comic talent, even if Ron’s look is now more inappropriately shabby chic than shabby).

Before he even gets to school at Hogwarts, Harry learns he’s the target of convicted murderer Sirius Black (the magnificent Gary Oldman). Black’s escape from Azkaban Prison has brought the presence of its guards, the Dementors, to the school to find him.

Black’s true history is revealed in a series of circumstances that bring to Harry more information about his deceased parents and their killer, Lord Voldemort.

Radcliffe handles these emotional moments with quiet accomplishment, showing us both Harry’s concern and hunger for power. In the finale, there is a brief glint in Radcliffe’s eye at the thrill of control that’s way more effective than any histrionics from Hayden Christensen in Star Wars.

Oldman steals the movie, though, and early, with his silent screams of mania on brought-to-life wanted posters. The bit is great because we know Oldman can play scary dudes, but even as Black’s restraint comes through, there’s more wily momentum in his performance than in the entire film.

Again, a who’s who of British actors show up for extended cameos, like treats along the path. David Thewlis makes for a dignified Remus Lupin, professor of Defense Against the Dark Arts. Alan Rickman’s delivery as Professor Snape makes the command to turn to page 394 in a textbook sound like a death sentence. And, filling in for the late Richard Harris as Harry’s mentor Dumbledore, Michael Gambon is less grandfatherly, more mischievous as the character is written.

Azkaban is passable as presented, but is perfect evidence for the obvious truth Potter fans must face. The only great Harry Potter movies will be those we create in our minds as readers.