YOU are flying at 37,000 feet, in a new state-of-the-art airlinerso how on earth could a child suddenly disappear from your plane?

This nerve-shattering question lies at the heart of Flightplan, a suspense thriller that transports the audience into the turbulent confines of an international flightand puts them at the very centre of a chilling human mystery as they jet from Berlin to New York.

Jodie Foster stars as Kyle Pratt, the frantic but fiercely intelligent mother whose deepest protective instincts will be triggered by a haunting in-flight nightmare: in the middle of the trans-Atlantic trip, her young daughter goes missing without a trace.

Or does she?

The dilemma facing the passengers and crew onboard is exactly the same predicament that audiences of Flightplan will experience: is Kyle Pratt (Foster), who arrives on the flight still reeling from the recent loss of her husband, a woman who has gone mad with grief or a formidably determined mother whose child is in grave danger that threatens the entire plane? Adding to the growing mystery is the fact that the name of Kyle's daughter doesn't even appear on the flight list.

Furthermore, neither of the flight attendants (Erika Christensen, Kate Beahan) can remember seeing the child on the plane. While Captain Rich (Sean Bean) and Air Marshal Gene Carson (Peter Sarsgaard) don't want to doubt Kyle's insistent claim that her daughter has vanished, all evidence points to the fact that Kyle's little girl was never on board.

What is the truth behind Kyle Pratt's distress? Who on board can be trusted? And just how far will Kyle have to go to get to the bottom of the harrowing mystery?

As paranoia and doubt mount among the passengers, Kyle is confronted with some of the most unsettling fears a mother could ever face - losing her child, having her very reality questioned and being trapped in a situation where no one can seem to help.

Pushed to the edge and fighting for her sanity, Kyle finds herself willing to go to unimaginable lengths to save her daughter.

At the centre of the mounting tension and spiralling human intrigue in Flightplan lies Kyle Pratt, a widow wracked with grief, and a mother who finds herself in an unimaginable position: trying to make an entire airplane's crew and passengers believe that her little girl has somehow disappeared from plain sight.

Jodie Foster plays Kyle, whose emotions during the course of the film are transformed from numbed grief to horrified shock to galvanised action as she stops at nothing to solve the gut-wrenching mystery that has taken her daughter.

As a mother of two, Foster felt a strong affinity for Flightplan from the minute she heard about the story from producer Brian Grazer.

"What really moved me about Flightplan was the idea of a woman who has lost her child and yet suddenly is forced to question her sanity because there's so much grief inside her that she has to wonder if she's going insane," says Foster. "Meanwhile, she's in this strange sort of international world of an airplane where people are naturally suspicious of one another, so the situation has tremendous tension and pressure to it."

Foster continues: "I also have always liked the idea of stories that unfold inside confined spaces. I like the intensity and how the story always winds up being about how people cope with one another and change inside that space.

"This movie is a thriller but it's also a personal journey - a glimpse at how one woman reacts under the greatest sort of stress and panic, how she pulls herself back from the abyss of grief and gets herself together.

"I think that Kyle isn't really so much heroic as she is absolutely driven. She might sometimes be brash, sometimes irrational, other times manipulative. But she will do anything she can to find her daughter."

Peter Sarsgaard, who plays an air marshal who reveals his identity during the flight, was impressed with Flightplan's sophisticated take on suspenseful storytelling. "I thought it was a terrific combination of genres," he says.

"To me, at first, it was a movie about grief, but then it transforms itself into a thriller and a drama and a mystery with lots of twists and turns. It becomes a kind of labyrinth. There's definitely something very Hitchcockian about it."