John McClane, the New York cop who took on single handed some men who took over the office building where his wife worked a year ago, is now at Dulles Airport waiting for his wife to arrive so they can spend Christmas with her family. But it turns out that a South American President who became a drug dealer after the US withdrew support, is arriving to be handed to American authorities. And McClane notices some men acting strangely so he follows them and they start shooting at him and he shoots back. McClane tries to talk to the Chief of the Airport police but the guy doesn't want to listen, so McClane gets the fingerprints of the man he killed and has his friend at the LAPD check it out. And he finds out that the man officially died two years ago. So McClane thinks the guy is part of a Black Op and tries to tell the Manager but before they could act on it, the Airport's system goes out. And that's when someone calls them and tells them that they've taken control of their system so they can't contact any of the planes who are arriving and give them landing instructions. And some of the planes have little fuel and among them is the one McClane's wife is on. McClane tries to stop them.