Julianne Moore once played Jodie Foster, taking Foster's role as FBI agent Clarice Starling in "The Silence of the Lambs" follow-up "Hannibal".

Now Foster returns the favour with "Flightplan", essentially playing the same maybe-crazy, maybe-not mom that Moore portrayed in last year's horror hit "The Forgotten".'

Moore played a desperate mother scrambling to find out what happened to the son everyone else tells her never existed. In "Flightplan", Foster's a desperate mother scrambling to find out what happened to the daughter everyone else tells her no longer exists.

The key difference is that Moore was safe on the ground, while Foster's hovering in the low-oxygen zone at 37,000 feet aboard a trans-Atlantic flight. The result packs nearly as much boredom into 90 minutes as the six-hour ride from Berlin to New York City.

The basic story is intriguing, and with Foster and supersonic producer Brian Grazer on board, there was a real prospect for a high-flying thriller.

The filmmakers rounded up a solid roster that features supporting players Peter Sarsgaard, Sean Bean and Erika Christensen. The performances all around, including that of two-time Academy Award winner Foster, are intense and frantic, but evoke little resonance or empathy.

German independent director Robert Schwentke makes a technically sturdy Hollywood debut, yet he ekes out little more than moments of brooding atmosphere and a few climatic chills from a screenplay by Peter A. Dowling and Billy Ray that moves from implausible to farfetched to absurd.

The movie opens with newly widowed Kyle Pratt (Foster) making plans to return home from Germany to Long Island to bury her husband, who died in a fall from their apartment building.

Kyle has a little fantasy in which she spends an evening with her dead hubby before heading to the airport with their six-year-old daughter, Julia (Marlene Lawston), an encounter that sets the stage for scepticism about Kyle's sanity once on board the plane.

After nodding off in mid-flight, Kyle awakens to discover Julia is missing. Kyle's anxiety turns to terror as a search orchestrated by the plane's steely captain (Bean) and a sympathetic air marshal (Sarsgaard) turns up no sign of Julia.

Passengers and crew, including Christensen and Kate Beahan as flight attendants, say they never saw the little girl, and the flight manifest shows Kyle was flying alone. The crew ultimately determines they have a delusional lunatic on their hands after they receive a dispatch from Berlin that Julia died with her father in the fall.

The first two acts of "Flightplan'' are merely dull nonsense. In the final act, the movie nosedives into preposterousness with sudden plot twists that are cheap, vulgar and none too surprising.

"Flightplan'' has a sharp reference or two to airline security in a post-September 11 world. The movie turns lurid and even farcical, though, in its attempt to capture Westerners' distrust of Arabs.

The cloistered atmosphere of "Flightplan'' brings to mind the summer thriller "Red Eye",' another listless mid-air tale, while the sight of Foster in narrow crawl spaces feels like a continuation of her last starring role in "Panic Room",' about a mom fighting back against intruders in her home.

Foster is stuck in panic mode throughout "Flightplan", blue eyes so wide they practically pop out of their sockets, pursed lips grimacing so tightly she looks like she's fighting back an epic case of airsickness.

Such a travelling companion on board a plane would be distressing. In a movie, she's just annoying.

"Flightplan", released by Disney's Touchstone Pictures, is rated PG-13 for violence and some intense plot material. Running time: 97 minutes. One and a half stars out of four.