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 how 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"