Airplane engineer Kyle Pratt (Jodie Foster) is heading home from Germany to New York on a double-decker Elgin 474 to bury her husband. But three hours into the flight, she awakens to find her young daughter missing -- and the entire flight crew, including Capt. Rich (Sean Bean) and Air Marshal Gene Carson (Peter Sarsgaard), claims that the child was never on board. Determined to find her daughter, Kyle searches the limited space of the plane, all the while trying to maintain her sanity.