Young flight attendant, Lisa Gates, is deeply in love with Adam. He ticks all the boxes except for one - he's married. His wife, Mary, is oblivious of their secret love affair. While Mary is away in New York to launch her successful jewelry line, Lisa spends a passionate night with Adam. He seduces her with love, expensive gifts and a promise to leave his wife once and for all. But during a routine flight to London, Lisa is shocked to see Mary sitting among the passengers. Her fiery red hair is not hard to miss. When Lisa attempts to get a better look at her, she's nowhere to be found. Even though she is not on the manifest, Lisa is certain that Mary is on the plane. Hours into the flight, Lisa is psychologically tormented with terrifying things only she can see. Taking matters into her own hands, she searches every seat but still no Mary in sight. Fear and paranoia take over as Lisa alerts the crew of a possible missing passenger. They search high and low, but Lisa's terror and erratic behavior worsens during the flight when she believes that Mary is out to kill her.Is Mary really on the plane, or is Lisa hiding something sinister from Adam? There's nowhere to hide at 40,000 feet.Fasten your seat belt -it's going to be a turbulent flight.