Flightplan ending / spoiler
Carson is actually a terrorist, working with that weird flight attendant seen throughout the movie (the one with too much mascara on). He drugged the girl somehow and hid her in the engine room. He is planning on blowing up the plane with the bomb that he planted in the coffin of Jodie Foster's husband (who was killed by Carson) and making everyone think that Jodie Foster is the real terrorist because she looks crazy. He tells the captain that she wants 50 million dollars, but he tells the captain that she will let everyone off the plane, as they are landing, originally to arrest Jodie Foster for being disorderly. Jodie Foster runs into the Captain just as the people are exiting the plane and figures out Carson's plan. Knowing that no one will believe her, she outsmarts Carson and tells him that he leaves the plane when she says so, making it look like she's still making demands. As Carson shuts the door, leaving only Carson, the weird flight attendant, Jodie Foster and her girl on the plane, Jodie Foster hits Carson in the side of the head with a fire extinguisher. She takes the bomb detonator from Carson. Carson pulls out a gun (his previous one was taken by the captain as he left the plane as was Jodie Foster's orders) and tries to shoot her with it, but she runs away towards the cockpit. After going through a series of air vents and crawlspaces and such, Jodie Foster finds her kid in the engine of the plane and hides in a compartment just as Carson comes. He trips into the engine area and Jodie Foster blows him up. The police figure that Jodie Foster is not crazy when she brings her kid out of the plane and they arent hurt. As the people of the plane gather in a warehouse in Newfoundland (where they were forced to land), Jodie Foster drives off in a minivan. The arab guy that pushed her into the side of the chair helps her with her bags. The girl asks if they are there yet.