The story goes that when Alfred Hitchcock conceived the idea for "North by Northwest" he really just came up with three action set-pieces — Cary Grant and Eva Marie Saint hanging from the faces on Mount Rushmore, the cropduster chasing Grant through a cornfield and the sequence that has bad guys pouring liquor down Grant's throat until he's too drunk to drive, then putting him behind the wheel of a car that is sent careening down a mountain.

For the rest, he hired a screenwriter to build a story around these bits of business, along with characters the audience would care about. It worked, and "North by Northwest" is still one of Hitch's most beloved films.

For "Mission: Impossible," director Brian De Palma (an odd choice, considering all the gory films in his mostly R-rated filmography, most famously "The Untouchables") also has three elaborate action set-pieces — a suspenseful caper set at a posh party, an intense break-in at CIA headquarters in Langley, Va., and a ridiculous but nonetheless thrilling chase on top of a bullet train that is speeding from London to Paris.

Unfortunately, the screenplay built around these action scenes is overly plotted and too dense to decipher in places, the characterizations are so superficial that their motivations seem cloudy at best, and one character who was central to the television series is played in a way that will wreak havoc with fans' loyalties.

But strictly in terms of action, De Palma certainly delivers the goods. (And De Palma fans who look forward to his trademark Hitchcockian touches won't be disappointed — from an overhead shot of a long spiral staircase to Danny Elfman's music, which occasionally takes on Bernard Herrmann overtones, in addition to variations on Lalo Schifrin's familiar TV theme.)

Tom Cruise is the big draw here, of course (he also co-produced), starring as Ethan Hunt, daring, a bit reckless and initially just part of the crew gathered by team-leader Jim Phelps (Jon Voight) for a dangerous assignment. (The film begins in a manner similar to the old television series, as Phelps is informed of the mission — should he choose to accept it — by an audio tape that self-destructs.)

Among the team members are Phelps' sexy, younger wife, Claire (Emmanuelle Beart), and a humorless operative named Sarah (Kristin Scott-Thomas), along with a computer hacker played by an unbilled star.

They are to attend a glitzy party to retrieve a computer disk that contains the names and addresses of secret agents, which allows for disguises, scary elevator rides and some high-tech tomfoolery.