(CNN) -- Entering his sixth year at Hogwarts, Harry Potter may not be able to see the finishing line, but he knows it's coming.
In "Harry Potter and the Half-Blood Prince," the trio of Harry, Ron and Hermione are on the trail of evil.
In "Harry Potter and the Half-Blood Prince," the sixth film in the Potter series, he's like a marathon runner who senses that he's got this course beat: He's still pacing himself, but there's a definite spring in his step.
Potter's confidence seems to be a product of Daniel Radcliffe's authority in the role as much as anything. He's decided he's the hero of the piece, and he's happy with that; Radcliffe plays him with such implacable conviction and such lightness, it's becoming harder to worry about the character's plight.
He can be reckless and impatient, but by now he's essentially untouchable. His chums may be prey to hormonal surges -- buckets of screen time is devoted to Ron's love life and Hermione's lack of same -- but our Harry stays focused. While Ron moons over his girlfriend, every night Potter takes a textbook to bed with him. Potter 101: A guide to Harry Potter »
This battered book of potions comes with scarily insightful scribbles by a former student, the titular half-blood prince, giving Potter a distinct edge over his classmates and that increasingly conflicted bleached blond, Draco Malfoy. More important, it also gets him in good with this installment's designated dodgy faculty member, Professor Horace Slughorn.
We know the drill by now: Slughorn has special knowledge that Harry must prize out of him, while the teacher's own leanings remain tantalizingly ambiguous. A special guest star in all but name, Jim Broadbent plays this mildewed academic with appropriately Dickensian panache and an undertow of sympathy (first spotted disguised as an armchair, the suspiciously solicitous Slughorn maintains at least one foot in the closet).
Adapted by Steve Kloves and directed (like Potter V, "The Order of the Phoenix") by the efficient, self-effacing David Yates, "Half-Blood Prince" is as brisk and nimble as J.K. Rowling's two-steps-forward, one-step-back narrative stratagems allow.
It risks annoying some fans by axing one significant character and a potential action show-stopper, but it's actually the overarching storyline that feels skimpy; the movie is replete with lovely, inventive design details and idiosyncratic effects work, while Yates' reluctance to pump up the bombast might be counted sweet relief after the latest bout of blockbusting overkill. iReport.com: "Potter" fans review the film
A trio of evenly spaced set-pieces do generate enough excitement to make this an iffy proposition for parents with younger kids; in particular Dumbledore and Harry's climactic cave expedition is an intense, nightmarish standout.
But for all this series' constitutional doom-and-gloom, what's truly charming about the Harry Potter movies is the rare privilege of seeing Radcliffe, Rupert Grint (Ron), Emma Watson (Hermione) and the others growing up before our eyes. Video gallery: See the stars now and then »
We've now had eight formative years -- the first film came out in 2001 -- telescoped into 15 hours or so of tumultuous screen time, and anyone who's stayed the course with them will feel a connection. iReport.com: Share your "Potter" review
Soon it will be time to let these kids go and find their own way in the Muggle world, but what rich, strange and wonderful home movies we'll have to look back on.
"Harry Potter and the Half-Blood Prince" is rated PG and runs 153 minutes. For Entertainment Weekly's review, click here.