First off, I don't want to give any spoilers, but the catchphrase on this poster doesn't exactly keep much hidden from the viewer...just sayin'.. A group of people from different backgrounds all board a plane for an overnight flight to Tokyo. Half way through the flight, the plane hits bad turbulence which scares everyone, but soon passes. However it causes one of the passengers to have a panic attack and start bleeding, and then almost immediately he dies. Not wishing to alarm the passengers anymore, the air hostesses move the passengers into economy class seating and place the deceased body in the cordoned off first class. The cabin pressure then drops and scares everyone (again) and so on and so on. It's a pretty good horror ride (snort) but very predictable and some of the characters will start to grate on you after a while. PS it's a bit unfortunate regarding everything that happened with the Malaysian airlines this year and a bit close to the bone to make a film like this, but that's probably easy to disregard once you get in to it.
