Severely flawed thriller about an airplane designer (Jodie Foster) who, after the sudden death of her husband, flies home to New York from Berlin with both his coffin and their 6-year-old daughter on the biggest jumbo jet you've ever seen. When Foster awakes from a nap in mid-air, she realizes the daughter has vanished - and yet nobody on the airplane even remembers having seen the girl.

Is there a conspiracy afoot, or is Foster going crazy? That's the question Flightplan's screenwriters Peter A. Dowling and Billy Ray hope you'll be asking yourself, but unfortunately they - and German film director Robert Schwentke, in his American debut - forget that what looks convincing on paper and maybe even during production can lose a lot of credibility when unspooled before an audience.

First of all, you know walking in that the movie won't just wind up saying, "Yep, Jodie's crazy, her daughter was never with her, the end" because then you'd have no movie. On the other hand, the buildup is so intriguing that the revelation of what is really going on is bound to disappoint.

So when we finally find out the truth, just in time for the third act, the "surprise twist" is woefully limp. Still, Schwentke, Foster & co. are game enough to keep the movie going, opting for a sort-of tense final chase around the airplane even though by then the audience has been taken out of the story by the sheer number of ill-explained plot contrivances.

Flightplan has one of those scripts where, in order for the bad guy's plot to succeed, a ton of random, impossible-to-predict variables have to fall exactly into place. Why is it, for instance, that none of the 425 passengers on board can remember seeing Foster board with her little girl? Because the film conveniently forgets the concept of the "departure lounge" where people would have seen them, that's why. Maybe if Foster was late to the airport, it could - but no. Then that would negate her getting on first (because she has a small child, naturally), as the movie has her do, so that none of the passengers would see the girl boarding with her. Except that if she hadn't been with a small child, the flight attendants wouldn't have pre-boarded her! Argh!

This is only one of about a dozen or so serious plot holes that mar the story and ultimately make for an unsatisfying film. And it's too bad, because the first hour is a really good puzzler. Maybe if the filmmakers had been daring enough to take their story into the Twilight Zone in order to solve the imponderable riddle of how a person could disappear on an airplane at 37,000 feet, Flightplan might have been interesting. As it is, it's barely even serviceable.