Considering that we've been following his death-defying adventures for two movies now, it's surprising how little we know about Ethan Hunt, the super-spy played by Tom Cruise in the Mission: Impossible franchise. Of course, action-movie icons aren't required to have deep inner lives; it's not as if we're desperate to know where James Bond's chauvinistic streak comes from or how Indiana Jones was able to complete graduate school while gallivanting around the globe. In general, all moviegoers are looking for in a hero is someone with a handsome face, a good personality and a mean right hook. Even by those thin standards, though, Hunt has always been a cipher. The first Mission: Impossible presented him as the only straight arrow in an agency filled with traitors and turncoats, while John Woo's misbegotten sequel transformed him into a lone wolf who spent an inordinate amount of time behind prosthetic facial masks. Both times the character lacked any defining personality traits apart from his dexterity in the field. So if nothing else, Mission: Impossible III co-writer/director J.J. Abrams deserves credit for turning Hunt into a recognizable human being. A celebrated television auteur (he's the creator of the cult spy show "Alias" and one of the masterminds behind "Lost") making his debut as a feature filmmaker, Abrams gives Ethan a newfound vulnerability and sense of humor to go along with his already established combat skills. We're essentially meeting a wholly different man here-call him Ethan Hunt Version 3.0.

The new and improved Hunt is only one of the reasons Abrams turned out to be an inspired choice to helm Mission: Impossible III. Another reason is his proven expertise at telling exciting yarns set amidst the world of secret agents and shadowy criminal masterminds. Week in and week out on "Alias," he and his writing staff (which includes M:i:III co-writers Alex Kurtzman and Roberto Orci) provide a mini-course in the art of constructing a great spy story. Every episode finds the show's core cast designing an elaborate plan to locate and retrieve a device (or, as Hitchcock preferred to call them, a McGuffin) that threatens the safety of the world as we know it. The mechanics of these devices are rarely explained and ultimately don't matter; the appeal lies in watching the heroine and her fellow agents dress up in cool costumes and fight their way out of tight spots.

As the show's fans are sure to notice, Abrams has modeled M:i:III after a typical "Alias" episode. The film opens with the battered hero in the clutches of his enemy, before flashing back several days earlier to show us how he ended up in that position. In this case, it all started when Hunt comes out of his self-imposed retirement to rescue a former protégé (Keri Russell) who was captured while on assignment. With the help of his team, which includes computer expert Luther (Ving Rhames, the only actor besides Cruise to appear in all three movies) and backup operatives Declan (Jonathan Rhys Meyers) and Zhen (Maggie Q), he saves the agent only to have her die in his arms. The man responsible for her death is psychopathic arms dealer Owen Davian (Philip Seymour Hoffman in a scene-stealing turn), who is currently in pursuit of a McGuffin called the "rabbit's foot." Hunt captures Davian during a superbly executed infiltration of the Vatican, but the crime boss is rescued by his well-armed minions as soon as he's back in the U.S. Not one to forgive and forget, Owen kidnaps Ethan's new wife Julia (Michelle Monaghan)-who knows nothing about his double life as a spy-and gives him 48 hours to recover the rabbit's foot in exchange for her life.

Much like its hero, Mission: Impossible III is constantly in motion. Aside from one or two quiet moments, the movie never pauses for breath, instead racing from one set-piece to another at breakneck speed. The fast pace is appropriate, though; Abrams knows that he's performing a cinematic sleight of hand and if he slows the proceedings down too much, the audience will catch onto the fact that there's no logical reason for any of this to be happening. This is not to say that the movie is incoherent. On the contrary, it's the best-told Mission: Impossible adventure yet. The script is lean and efficient, with every scene driving the action forward.

When Cruise first handpicked Abrams to direct M:i:III, there was some concern about whether a TV director, even one known for staging stellar small-screen action sequences, would be able to handle the pyrotechnics expected of a summer blockbuster. While it is true that Abrams isn't as inventive as his predecessors, Woo and Brian DePalma, he proves his mettle early on. In addition to the aforementioned scene at the Vatican, the opening rescue mission is terrifically staged and towards the end of the film there's a breathtaking moment where Ethan leaps off a Shanghai skyscraper and swings to another rooftop high above the city. The stunts are performed with a minimum of digital effects as well, which adds to the excitement. And at the center of it all there's Tom Cruise, who finally recovers his movie-star legs after a year in the tabloid spotlight. The actor has never looked more at home than when he's dodging a jackknifing truck or threatening to toss a bad guy out of an airplane. At the same time, Abrams allows him to have a little fun with his character for once, which goes a long way to winning over the audience. If Cruise does decide to make M:i:IV, let's hope that this is the version of Ethan Hunt that returns.

-Ethan Alter