Like a lot of stylishly persuasive thrillers, Flightplan is more fun to watch than it is to think about. There's much to admire in this hermetically sealed mystery, in which a propulsion engineer and grieving widow (Jodie Foster) takes her 6-year-old daughter (and a coffin containing her husband's body) on a transatlantic flight aboard a brand-new jumbo jet she helped design, and faces a mother's worst nightmare when her daughter (Marlene Lawston) goes missing. But … mehrhow can that be? Is she delusional? Are the flight crew, the captain (Sean Bean) and a seemingly sympathetic sky marshal (Peter Sarsgaard) playing out some kind of conspiratorial abduction? In making his first English-language feature, German director Robert Schwentke milks the mother's dilemma for all it's worth, and Foster's intense yet subtly nuanced performance (which builds on a fair amount of post-9/11 paranoia) encompasses all the shifting emotions required to grab and hold your attention. Alas, this upgraded riff on Hitchcock's The Lady Vanishes (not to mention Otto Preminger's Bunny Lake is Missing ) is ultimately too preposterous to hold itself together. Flightplan gives us a dazzling tour of the jumbo jet's high-tech innards, and its suspense is intelligently maintained all the way through to a cathartic conclusion, but the plot-heavy mechanics break down under scrutiny. Your best bet is to fasten your seatbelt and enjoy the thrills on a purely emotional level -- a strategy that worked equally well with Panic Room , Foster's previous thriller about a mother and daughter in peril. --Jeff Shannon weniger