On a plane at 40,000 feet, Kyle Pratt (Foster) faces every mother's worst nightmare when her 6-year-old daughter, Julia, vanishes without a trace in mid-flight. Kyle desperately struggles to prove her sanity to the disbelieving flight crew and passengers while facing the very real possibility that she may be losing her mind, as all evidence indicates that her daughter was never on board. Kyle can only rely on her own wits to solve the mystery and save her daughter.