On the July 4th holiday, an attack on the vulnerable United States infrastructure begins to shut down the entire nation. The mysterious figure behind the scheme has figured out every modern angle--but he never figured on an old-analog fly, John McClane, in the digital ointment. It's the beginning of the holiday, but New York City Detective McClane isn't celebrating. He's had yet another argument with his college-age daughter Lucy, and received a crushingly routine assignment to bring in a young hacker, Matt Farrell, for questioning by the FBI. But for McClane, the ordinary has a habit of exploding into the extraordinary--abruptly hurtling him into the wrong place at the wrong time. With Farrell's help, McClane slowly begins to understand the increasing chaos surrounding him. An attack is underway on the vulnerable United States infrastructure, shutting down the entire nation. The mysterious figure behind the scheme, Thomas Gabriel, stays several moves ahead of McClane as he implements his incredible plans, known to uber-geeks like Farrell as a "fire sale" (as in, everything must go!).